For me Bitcoin is not scary at all, because the nature of business shares such as Cryptocurrency trading is always like that, there are times when prices go up and also when prices go down, so again I will never be afraid if the price of Bitcoin decreases, because history has proven Bitcoin prices always go up and up every year.

I am always reading a lot of articles about an altcoin. Moreover, I also research this forum for any scam issue or something else. The next step is to check the website and the team members. The last step is reading the whitepaper and checking the community numbers.

whether you believe it or not, its coming. just like how smartphone replace most of the stuff we have. 

It is impossible to predict what will happen after such a long period of time, because I simply do not believe that there is an opportunity to calculate such a large amount of time and calculate serious opportunities for this.

it all depends on who wants to invest, because if you choose the long term it would be great for us to get the desired benefits, because we can choose the price of coins that we hold for sale

There are so many merchants worldwide accepting bitcoin, In my Area there is petrol pump and restaurant  that accepts bitcoin payment for fuel and food.

therefore, ethereum has a bright future because the platform is widely used by ICO, so this coin is a very strong coin and often has a good price increase

If I had 10.000 USD and I must invest all of that money in crypto, BTC will be my number one investment with 50% on second place is Ethereum with 25% then EOS with 15%, other 10% I probably invest in smaller cap altcoins like DATA streamr.

I think that now you can invest in any cryptocurrency as it will be beneficial for the future. Due to the stability and low prices, a major breakthrough is possible. And now it will be possible to grab a good enough piece

i dont think bitcoin will be replace by any altcoin
all altcoin is traded to bitcoin vice versa
for me how can other altcoin dominate the market if they cant be traded in other altcoin like bitcoin
but who know what can happen someday its just my opinion

With OP's questions there's a lot of coins/tokens that popped up in my mind. 1st is electroneum with this project there's a potential of getting a real deal in mining and payment system especially when there was a bull market it was $0.26(more or less) considering the ico price was $0.01. But my own pick will still be INS, insolar previously ins ecosystem have a great team/people who work hand in hand for the success and future of grocery industry considering its undervalued price, low supply and of course the goal of its project.

Yesterday I heard XRP was accepted as a payment method in advacash. It is breakthrough!
ripple should show positive dynamics after this news.

I don't think it's gonna rise like it did last December due to a couple of factors...  Everything was going crazy then, making new highs and bored TRX holders now prolly hold froze their TRX to hold Tron Power to cast their votes.
I did just that, and it's fun.  Lol.  I'm actually thinking of buying more TRX to increase my voting stake. 

Though eth is one great project that must be invest in but I don't advice putting all eggs in one basket as it will be cool to diversify your investment , so do some research on other coin that can be invest in and make a cool option.

I see no reason why we should have a bull run in december. The next bull run will certainly be much longer in coming. I do not expect it until the end of 2019 or even later. This gives me the opportunity to continue to buy cheap coins. That is why i think that is not so bad.

of course because to be rich through bitcoin and other crypto is the key is to always be patient and keep trying because if you want to be patient and try certainly your business will not betray the results
and bitcoin is also very promising to be a long-term investment

I started trading by reading a lot of knowledge about trading crypto on websites. I also get a lot of guidance from my sister. So I started buying Bitcoin and get profit.