Ask general questions and you will get general answers.
So general (usually unhelpful) answers
Anything up to 20 BB can be an open shove, it just depends on a lot of factors which like position, hand type, player tendancies, tournament strucuture( are the blinds going up soon? etc)
you usually want to 3bet light with stuff that plays decently against a strong range. Stuff like 87s plays a hell of a lot better vs a strong range than A2s does for example (becuase against a strong range you will end up against High Ax hands more often)
You don't have to just open shove 20-30 BB stacks, Just raise as normal and either shove flops, or get it in over two streets.