Most people probably have figured this out but as long as you don't do anything that will cause multiple people to complain to an admin (or piss off an admin directly) then whatever you're doing is probably fine.
I see people getting banned for 2 things far more than offclassing:
1) adding up to pugs as a combo member and not joining mumble/refusing to speak even when asked too (especially prevalent in super late night pugs)
2) captains picking people that they know they have personal/gameplay issues with, and then subbing them out in frustration.
If you're not doing either of those two things and you're not blatantly trolling/pissing off an admin it's pretty hard to do anything ban worthy