a
b
a (bb vs but?)
a
a
a
Whatever PaintingByNumbers says will likely be the right 'vacuum' answer (and these are vacuum questions after all). He is GOOOOOD at the GTO stuff!
However, most (all?) of these are so close that reads/dynamics/stats etc are so ridiculously important, and thus 'vacuum' GTO analysis is only of so much interest.
Also, I am sure you could be a big winning online player without ever doing any of these things! In fact, I suspect that pledging to not ever do any of these things might immediately increase the win rates of a large of majority of players (except for the A2 hand).