I think that all clients (to be more "normie-friendly') should do a thing where if someone accidentally posts their nsec it just posts a bunch of xxxxxxx's or something.

Bitcoiners are (in general) good at private key management, but, its a good way of removing a foot-gun to help with more mainstream adoption. If they really wanna post their nsec, maybe if they throw a space in there, it won't get recognized for example:

"ns ec1ae46...