When cryptocurrency was first introduced, some people didn't believe it and found it a joke, moreover cryptocurrency can work in real life. But as time goes by, people are increasingly interested in joining cryptocurrency and are competing to invest in it.
So that digital assets can be accepted by the wider community, then there must be obstacles that are passed. One of them is the legitimacy of the government, which requires price stability and allows the global reach of cryptocurrencies as a means of payment.

Most investors consider bitcoin to be the best speculative asset at the moment.  On the other side, Bitcoin has characteristics that have the potential to provide greater value to investors compared to gold.  Bitcoin and Gold can be used as assets that complement an investment portfolio.
An investment principle to note is never to put all your money into one type of investment.  Although bitcoin looks better and tantalizing, you should not just put all the money into bitcoin, Set aside a portion of your money for other investments.  Remember, the choice is yours.

The loss you experienced was very painful, especially in large quantities. While you are still learning and trying, Hope is always wide open for you. The loss you will experience will be the most valuable experience for you, for the future you have to set a good investment strategy, don't focus too much on one project, you have to find some projects to invest, then the risk of loss that you experience is very small.

Uniswap has upgraded its ranking to become the second largest DeFi protocol by total value locked (TVL), $ 1.32 billion in locked funds. Uniswap TVL has increased nearly 75% in the 24 hours following the announcement of UNI's liquidity mining incentives. In one day, Uni has been listed on several top exchanges, uni has shown such impressive qualities that it has taken some by surprise with the performance of the Uni which was able to break a nearly 75% increase in a very short time.

40% Bitcoin
30% ethereum
10% litecoin
20% for short-term trading.
You have to set an investment strategy according to market conditions, don't focus too much on just one or two coins, BTC and ETH are the best choices, besides litecoin there are many other coins that deserve to be included in your portfolio list, especially now that defi has given a new color to the crypto market that you deserve to consider.

Even though most of the coins in your wallet have no value anymore, it will be a very memorable personal collection, Moreover, in your coin list there are favorite coins that were featured at that time. Now just let the coin be a decoration in your wallet, while waiting for the miracle that makes the dead coins come back to life, you should focus on coins that can benefit you.

Bounty hunters will continue to hunt for profitable projects for them, but the big problem is that bounty hunters are always victims of fraud, because there are so many scam projects that make bounty hunters disappointed. Now the bounty hunter is a little relieved, because there are social media campaigns that pay participants using Bitcoin. Although the results obtained were not many, but they will feel happy when they receive a payment.

The founder is very serious about developing this project, they will continue to make improvements so that they can continue to survive in cryptocurrency. Returning the funds is proof of the seriousness of the founder and is a very effective step to gain investor confidence. They won't just leave the project, Because sushi has a bright future, and the founders are already aware of it.

Uniswap and sushi are the new faces of cryptocurrency that have become excellent in a short time. Even though it is still a new coin, but these two coins were able to attract the attention of investors to make them one of the coins that could be relied on at this time. Sushi (defi) always experiences better growth, while the Uni is still very vulnerable to being dumping at any time. Hopefully these two coins will become the most valuable assets in the cryptocurrency world.

Maybe we are in the same boat, but has a different story, I was once invited by my friend to trade at Uniswap, but i never did, after my friend got 400 Uni for free, I was very sorry and upset with myself for not following my friend's invitation. Maybe we haven't had any luck yet, but there's still a chance to get something good the next time.

What is your goal in buying an Erc20 that is already used by someone else.?
What if the wallet you have bought is not completely secure, Because someone doesn't throw away the private key after their account is sold to you.
You should consider your intention to buy someone else's Erc20, because in cases like this, it is very vulnerable to theft of assets in the wallet.

I prefer to use fiat money for shopping, because the process is easy and practical,

Bitcoin and Ethereum, because bitcoin and ETH are commonly used and have a low risk.

Yes, I will buy some high-end coins when the market price is down, and will sell them again when the price goes up again.

Game applications such as slot games or gambling.  Slots are very popular with all people, while gambling still dominates, such as football betting, horse racing, and other games.

Everyone has different tastes, they have their respective mainstay coins and are completely the best choice for them. Of the many coins in the crypto market, have advantages and disadvantages of each. Despite having different flagship coins, As traders we have the same goal, to avoid the risk of loss, we must always monitor market movements so as not to miss the ship when the green light is on.

Overall, I totally agree with what you said, Bitcoin Cash is one of the best coins and a lot of traders have high hopes for BCH. As one of the best altcoins on the market, I always check the movement of the BCH chart, because besides ETH, I also keep BCH in my wallet. If the predictions made by several experts do come true, so my waiting has not been in vain.

As before explained, crypto has a great future, as real evidence, most countries have started to legalize crypto, although fiat currency is still an official transaction instrument recognized by the state, but cryptocurrency already dominates in several countries. If cryptocurrency is adopted en mass, It is very likely that in the future cryptocurrencies will be parallel to fiat currencies.

What is the reason you are selling the Ethereum that you have held for a long time? 
If you need money for personal use or buy something very important, there is no more reason to hold the assets that you have held, Moreover, you have received 20% profit from the investment that you have done so far. But if you want to buy another coin to accumulate profit in a short time, you should consider your intention to sell ETH, because as you said above, ETH is one of the best coins, so something good always gives the best results.

You can buy as many defi coins as you want, Moreover, defi is now a trending topic in this forum, Very many investors have bought defi coins and kept them in their wallets. But you should not be too passionate when investing, you must know when to buy and when to resell, because if you are wrong when making a decision, then the risk is you will lose the money that you have invested. 
My advice, make quality investments, do not by quantity.

After doing very mature research, then we make decisions based on the type of project according to their respective tastes. Currently the defi project is dominating the market, very many investors who took part in it. For me personally, prefer to use a long-term investment strategy in the top coins, such as ETH, LTC, BNB etc. Even though the profit I got was not too much, the risk of loss I faced was very small.

Scammers have always been parasites in the crypto space, throughout the history of crypto projects have never been free from scammers, starting from ICO, IEO and DEFI. Their presence is very disturbing, thus making investors suffer huge losses. Investing in crypto projects is very risky, but we can avoid it by researching and understanding the direction and goals of the projects we are going to invest in.

The risk that is often faced by Bitcoin users is a lack of understanding of the nature and workings of cryptocurrency, They don't know when to buy, sell, and so on. Before investing, you must know the ins and outs of investing so you don't experience losses. The fluctuating price of BitCoin allows us to make a profit. Therefore, we can get a significant profit if we carefully observe the trend of price changes.