Now there is a lot of talk about the fact that there is a lot of scam and there is practically nothing to buy, I think that this is partly true and now it's worth to be extremely cautious with investing.
In your model, it looks like altcoins artificially supported by Bitcoin. I think that the alts are still too attached to Bitcoin. And I hope soon it will end.
Oh God, I have not seen this one yet. I agree that you need to be very cautious in the crypt, I try to invest only in stable and old coins, it would not give quick money, but it's more secure..
This is a difficult choice, but now I would choose the Ethereum because it is really a stable and promising coin. I think that it is worth concentrating only on one coin.