Now, there are still some things I don't quite understand. Resistance Chewie not being able to fire when a ship flies off the board is disappointing (it seriously wouldn't even be close to an issue and instead would have been a fantastic risk/reward mechanic).
I'm totally with you on this. It wouldn't be overpowered at all, IMO. However, it does say in the Rules Reference that if any part of a ship's base is outside the play area, that ship has fled the battle. I suppose thematically Chewie wouldn't go ballistic over a friendly ship running away, even though in game terms the ship is destroyed. Normally I don't bring fluff into the rules, but they've done such an amazing job with Heroes of the Resistance that I can't help it.
I can see it still being fine thematically. It would be like him being outraged that someone isn't keeping their honor and instead is fleeing from a battle, and he gets even more aggressive in his desire to destroy the enemy quickly so he can chase down the traitor.
What happens if it's han running away? What does chewie do when he catches him?