From the list of coins you're holding the only one I will advise you to hold there is Cardano. I don't know about this Vechain, Flexacoin and other ones you have mentioned. Cardano alone would have made a better choice than buying some extra crap coins. And between Dent and BAT, I will advise you to choose BAT, there is no need for DENT.
Other choices you should also consider are ChainLink, BNB, EOS, Tron, Synthetix Network T, and ZRX. You should look into these and know whether there are any you would like. (These are just my suggestion and you must act as per your due diligence. Take time before spending, that's all).
I'm not into Bitcoin really but looking for a high reward possibility coin.
I don't know why you're not investing in Bitcoin. Bitcoin is a good coin and it works for me most of the time. Definitely you may regret one day or other for missing out bitcoins. Many people ignore bitcoins just because of its high value. But you must understand that your $100 in bitcoins may turn to $1000 very easily whereas no other altcoins may perform or may not in similar rate. Bitcoin is 99% has such a guarantee and other are having less than 10% of such a guarantee.
All I mean that you do not need to buy one whole bitcoin to hold. Anything like 0.01BTC or 0.1BTC also must be a very good investment for long term based planning.