good points specially the second one. i always tell people to stick to only a small number of coins and unfortunately i keep seeing people with long lists of coins they have invested in for some weird reason! i have actually seen someone who held about 50 different coins and tokens and was waiting to become rich but in reality he was losing more money that one normally does.
about your #4 i have to say i don't like telling others what i have invested in, specially friends who have no idea what cryptocurrencies or investment is! sure if someone is already familiar with the market, tell them but not if they are not.
I used to be one of those people. I thought that it's best to mimick the overall trend of the entire cryptocurrency market as a hedge against a small number of coins falling. I've since learned the error of my ways. The main problem with holding many coins is that if one of them moons, it will only be a small amount you make, yet if the entire crypto market crashes, there is no hedge anyway and you'll lose value regardless. You can see this currently with every single top 100 coin falling. So much for diversification, it would not have saved you!