VinDAX seems a good exchange with lots of coins. I think a good exchange support at least 100 coins and you can add easily new coins to it with low fees.

I sometimes win and sometimes lose in crypto trading, but overall I can increase my BTC wallet by 5% after transactions. It's a gamble.

I think banks are controlled by Goverments, and Blockchain won't. If Goverments issued own cryptocurrency based on Blockchain, it would replace some bank functions but not all of them.

I think TRON is a very popular coin, after BTC' price halving the USD price of TRON will be doubling by the end of 2020.

I think after BTC reward halving the mining will be less profitable, additionally over 80% of BTC max supply have been mined, thus BTC's price will be slowly increasing. Maybe it won't reach $20,000 by the end of 2020.

I think ETH has a good future, because its price is increasing significally and you can mine it with gpus.

I think BTC is a good starting point to buy. You can build a diversified cryptocurrency portfolio with top or emerging coins.