Before, or rather in a better condition, a good ICO have the tendency of giving  a very good profit which can be used to buy Bitcoin but in reality now, ICO have a greater chances of taking the funds you have thus leaving you with nothing as well as no funds to buy Bitcoin. Therefore, considering the current circumstances, it is better buying Bitcoin and be safe from most unnecessary risks, unless a new trend starts just like that of DeFi, and you were able to make enough gains, then buying Bitcoin would be a nice idea.
Lastly, another reason that makes Bitcoin worthwhile for buying this time around is owing to the types of attention and investors coming in, hence holding for long term would be a nice idea but first know the right time to buy in.

Looking at the current ranking on coinmarketcap, it is still now on fourth position, with USDT above it and LTC below it, however I do not think that XRP will hold that position for long owing to the challenges before them, that is, the SEC case and the delisting being started by many exchanges like Coinbase. That is to say, as we approach the delisting day there is every tendency that LTC will take over the fourth position in coinmarketcap and if care is not taken or if the case lingers more than expected, then it might fall further down the rank because funds from it will be flowing to other altcoins, and if there should be any sort of altcoin season, then we will be seeing more altcoins overtake it, unless the SEC case is tackled faster and positively.

I think some of these predictions are unrealistic such as that of XMR, that is, from current price of $158 to $3000, that is way too much remember that although it is a very good privacy coin, there are still other privacy coins which will share that attention with it, not only that, altcoins like Ethereum are still there to take much of the attention. I wouldn't go into others also, but let your purpose of investing in them be about what they offer and not the price so that you won't be disappointed at the end; to be frank predictions has been found not to go as predicted. However, my own picks for 2021 starts with Bitcoin of course, followed by Ethereum and ends with ADA, maybe for now or maybe later I would add another.

Commenting about the price; one of the things that adds an increase in a coins price is publicity, that is, what efforts has the team done to bring their project to the eyes of many audience. There are already many altcoins in the market even scanning through top 100 in coinmarketcap can be herculean task for some people, hence in order to make people aware of what you offer, you need to have an active social media channels. Also, having an active social media presence is one thing, having a good and active community is another as they are the ones to share the news.
Furthermore, I do not think it makes sense bombarding negative tweets here and there, if you want to stand out, then get to work, work and prove that you are different, then let the products and services do the talking. Lastly, if you want to hold long term, try and understand the team's urge towards bringing about a decentralized system and sticking to it, because saying it is different from doing the needful and sticking/continually working on it.

One of the things I think you should know currently is that, a lot has changed this time around and the current price growth of Bitcoin is a prove to that, that is, much attention are on it and a selected number of altcoins, which means that, there is every possiblity that BCH can't perform as before because people have known much and understood much as well.
Therefore, in my own opinion, comparing BCH and LTC, there is a very big gap between them, LTC on one hand is a reputed altcoin from a trusted team but same cannot be said of BCH, that is, it is plaqued with many bad reviews. Hence, I find it worthwhile holding on to LTC than BCH whose future is not heading to anywhere.

Thanks for list though but when comparing all these upcoming exchange airdrops to that Uniswap and even 1inch, a big difference is spotted, first they didn't announced it hence allowing them the ample opportunity to reward those who put in their best, but for some that already announcing it, the end results would be more traders for the sake of the airdrop and lesser reward. Also, it could be those exchanges are looking for a way to boost their trading volume and this airdrop scenario has offered them that, but another question is, are they really reputable exchanges like their counterparts and will they deliver as anticipated. Nevertheless, no harm in trying but let's endeavour to make sure it is worth it.

Looking back on the case of XRP with SEC, it would be difficult to predict the price of XRP or what XRP will be or grow to next year. To add more to it, some exchanges are already giving a timeframe of delisting it, and with this, makes the future of XRP shaky thus impacting negatively on its growth next year.
Also, currently, no one knows the step other exchanges like Binance will take towards this issue and if exchanges like Binance follow the path of others, this will also cause more selling activity on XRP thus more price drop and hence more uncertainty in its future.
Furthermore, if the issue with XRP keeps escalating, there will be no platform that will like to partner with it, since the future is unclear and confusing; so for now, I think 2021 will be a tough year for XRP.

No one can actually and correctly predict the future, hence we can only but assume. In my own opinion, for a coin like XRP it will be tough for it be out of existence it can only but drop badly in value. However, looking from another perspective, it can also be the end of XRP if the team gives up, you know working on a project or idea comes with motivation, so if the price drops terribly and the team losses the motivation to continue working on it, then it would be the end of the XRP but all these will depend on the outcome of the case with SEC. Furthermore, if the case ends in their favour and the team works harder, it will take time for XRP to go back to its position on coinmarketcap but at least growth will be witnessed.

Anyone buying XRP now is only but taking a very huge risk unless the person is doing so for trading purposes which also do not have a clear direction for now, also currently no one can point the direction XRP is heading to, not even the team because they have their hands full and tied up at the same time. Going further, in as much as the delisting from exchanges will leave a very bad effect on the price of XRP henceforth, in the case of their partners, it will also make them lose a lot as the trust those partners have towards XRP will be shaken.
Nevertheless, it is better staying afloat and watch what will become of one of top altcoins; the final hit that will make the price drop even more is when other bigger exchanges showcase their own stand on this XRP matter.

It is and has been already bad news or bad end of the year experience for them since the SEC case, that is, more holders have been selling because none want to loss a big chunk of their capital to holding since there is no headway yet for them. Also, with Coinbase delisting XRP, is already adding more reason for holders to sell in huge numbers this is because more exchanges will likely follow suit, and since exchanges is one of the driving forces behind the growth of most cryptocurrencies, it means that as more exchanges delist, the price of XRP will dump even more. Therefore, following all these, there is no crime selling all your holdings, moreover there are still better coins like Bitcoin and Ethereum, and if XRP is really worth it at the end, you can still buy back but for now, better safe than sorry.
Lastly, no one knows if Binance will take such action as that remains within the team to decide, but if they should, then it will be a very big blow to XRP, as it will lose a lot.

Scams in this crypto space has come a very long way and has lasted for a long time, even till now it is coming up in more advanced ways which ranges from airdrops to bounties and even most projects which were thought as good projects; so where can one actually start from. However, I think the best way to start from is doing our best to verify most projects before getting involved, even if it is airdrops, make sure the team are serious and so on. Also, the best way to reduce scams is when we stop running after hyped projects, taking the DeFi projects as a case study, it started on a good note but today, we have seen various levels of scams and many are still coming up today; so the best way still remains making your own research first and investing the funds you can afford to lose.
Lastly the same way some scam projects leveraged this forum to succeed is the same way some legit projects leveraged this forum to succeed as well, but however the most preferred way to run away from scams without taking chances is by going for top coins like Bitcoin and Ethereum.

Ethereum is occupying the second position in coinmarketcap hence can be easily seen, thus It's not as if they are not aware that Ethereum is the best altcoin and it looks like it will remain that way for a long time because no altcoin currently have the capability to beat Ethereum but however I think they are asking to know the altcoin they will invest in that will give them a reasonable reward or gain after a certain time and not an altcoin whose team can easily exit scam as seen in most upcoming projects nowadays. Also, looking at the way most new projects leverages hype to grow at the Initial stage and then dump terribly after a while, people needs to be careful and hence asking all the questions they need in order for them to make the right investment choices.

It looks like the trend has changed now, that is, if you trade in some Dex exchanges you will be qualified to get their airdrop like in the case of UNI and 1Inch, actually it is a good idea at least to reward users who believes in the exchange. However, it would be wise to be careful and gets the facts right henceforth with other forthcoming exchange airdrops because scammers don't joke with opportunities like this to create theirs and make their money. Also, with the number of exchanges which will come up just to do this, one will only but pause and ponder how their long term sustainability will be.
Nevertheless, there is no harm in trying, since the founder said so in an interview, maybe it's worth giving it a shot.

The market has changed tremendously from what it's used to be or from what is normally experienced. Before now, when Bitcoin rally Altcoins doesn't because a lot of people always move funds to Bitcoin in order to profit more from it, hence causing the dump of altcoins. But nowadays, with Bitcoin rally some altcoins are still moving up which are mostly within top 100 in coinmarketcap, but their movements however can't be compared with that of Bitcoin. On the other hand, most people are still believing there will be an altcoin season, but that looks like it is going to be tough because Bitcoin dominance is not slowing down and Bitcoin on the other hand is looking towards leaving another ATH. Therefore, to answer the question to the best of my understanding, I would say a very little number of altcoins follow Bitcoin rally.

Most times it is very important to be mindful of most sort of pumps witnessed in the market. Most especially when a token that looks questionable with low volume all of a sudden starts pumping hard, in my own opinion, when such happens it is the best time to sell that is if you are holding and move on, rather than buying because following such pumps always ends in a terrible manner. A dying project can get pumped by the team to attract users and then dump on them, it has happened many times and will keep happening because there are people who are easily swayed by pumps without minding what the project is all about or what the use case is all about or what is even causing the pump, what they care is to get their gains while getting trapped in most cases.

Harmony is a good project at least the team has tried their best to maintain a good growth and development right from launch till now and currently it is occupying a good rank on coinmarketcap although not top 100. Also what I understood from projects like Harmony is to study them appropriately, their ideas and the team's quest to actuallize it, then invest based on your research, this I see as the best way as it might take time to reach a good level of attention but investing in it based on predictions or based on what you thought the price will be within a particular time frame is what brings about disappointment and lack of understanding of the project. However, of course it will touch 500 sats but no one knows when and this also comes with the condition that the team continues working hard.

DeFi projects here and there but only few are really performing well with a lot of them no where to be found, and as such investors left to wonder if they did the right thing. To be frank, after looking at a lot of Defi projects it is obvious that the first of them which actually started the idea and hype are the ones that knows what DeFi is all about and hence working towards it ever since but all these new ones can hardly be relied on because after their pre sale or IEO, the true nature is made known.
So in my own opinion, Defi projects are already much and they all offers similar ideas hence it's better to be highly selective on them, moreover holding long term can even be a bad idea as the team can exit scam anytime.

Of course there will be more and more upcoming projects be it DeFi or ICO but what matters is going for the right ones and how can one possibly know the right ones, it is by performing an in-depth research on each and everyone of them. This is very neccessary because most project team are now deceptive and can go to any length just to convince their investors that they are genuine but once gotten the funds excuses will be the order of the day and possible death of the project. Therefore, it is very important to look beyond hype and focus on the potential of the project thus making a good decision.

XRP is currently facing SEC case and until that is taken care of, the price will continue to drop, because more people are losing interest already, more people are selling already because they don't want to lose big time and it's obvious that the more this case stays, there is every possiblity long term holders will likely sell to save their funds and be on the safer side. Now, about the price getting to $1, will first depend on if the case is solved faster and XRP regained its value from the eyes of investors, when that is done, more products and services will need to be developed so as to give people a thing to go for which will then attract more users. But all these are still speculation until the big issue is solved and that is, SEC issue being taken care of.

Looking at what XRP is currently facing, that is, the SEC issues and challenges from exchanges, the best thing to do at this point is to stay at bay and watch things unfold. Before this was thought to be a fud but it is clear that, it is more than just fud but more greater than we can imagine yet hence buying the dip would be a very bad idea because one doesn't know how long this issue with SEC will last and what will become its fate at the end. In addition, with the price doing down more, no one can predict the price it will get to, because the more the case lingers the more people panic and the more they sell, hence more price dump. Thus, in my own opinion, it is better to sell, be at bay and watch things unfold.