[JacJacAtk]

I don't think the first one's that trivial a fold. If you fold and BB wins, you're the new shorty and will have to win at least one showdown to avoid bubbling. If you call and can check it down, you're not grossly worse off (in the cases where BB wins), and you increase the chance that BB busts this hand. The possibility that button will shove and try to get you to fold is there, but given how likely 3rd is if he hits the flop and does this, you can probably just call anyway to protect yourself from the times he tries to push you off and you might have hit on the turn/river to eliminate BB.

All that said 52o is really terrible, and I'm not sure the implicit collusion advantages are worth it in this case. I wouldn't fold much here, though.