If your dog destroyed your TIE fighter expansion, then you don't have a TIE fighter expansion anymore... do you?

Yes, Z-95's can swing both ways... so can Y-Wings. You can use either for Rebels or Scum. They are the same ship, have the same dial, stats and model... they are just painted differently. You do need to use the correct cards and base-inserts for the pilot you are taking though.

A TIE and TIE/fo are different ships. They have different dials. They have different stats. They have different models. You can paint one like the other, but that will not turn one into another.

Fluff wise, I get it. If you want to on your table at your home, fine. Just don't bring it to my tourney or I will ask you to change your models or your list.