In my experience in crypto, as well as those I've spoken to, I think #2 is particularly salient. Just speaking from my personal experience, I have failed to accurately assess the risk I'm willing to take, and that's cost me. You're absolutely right about making emotional decisions on the fly; I could have minimized my exposure by doing a risk analysis and setting some hard limits before I went anywhere near an exchange.

Live and learn I guess. Great post, though. The basics always bear repeating.