Just don't buy when price is increasing. You should always buy during a bearish run. If price doesn't drop for a while after you buy you are doing something wrong. Don't try to buy from absolute bottom, you cannot time the market.
I don't think you know what "too big to fail" means. Insurance companies might be too big to fail because they have tons of contracts with other parties and failing to fulfill these contracts might drasticly hinder whole economy. Thats not applicable to bitcoin.
You are not diversifying anything by buying both. In order to diversify you need hold assets with negative or low correlation. Stratis and waves have very high correlation. And the fact that you can't decide between waves and stratis says that you didn't even read whitepapers and you should not invest your own money. Go buy some government bonds.
Bitcoin is a secure, censorship resistant store of wealth. Brightest minds in the field is working on the scaling problem. Ripple is an interbank payment protocol that does not need a token to work.