>>346334023
weightpainting is a pain point for everybody, don't feel bad if you have issues with it, pretty much everyone does

https://www.youtube.com/watch?v=aPz0QpfwJCk

this tutorial is long but actually good, might help

as for the viewball, is this an issue you have with one avatar or with multiple avatars? sounds like something that shouldn't happen, hard to help you here without having the project files and checking things in it