So this mission is coming up for my Rebels and I am wondering if I am missing something here. Can the Rebels only claim 1 mission token per round? But the Empire also gets 1 per round unless all the doors are open, but also claim mission tokens just by dealing 5 damage to them? If the Empire only needs 1 more mission token claimed than the rebels, how are the rebels supposed to win if the Empire takes even a small lead?

I'm hoping that I missed a rule somewhere that allows Rebels to claim mission tokens outside of the one per status phase. My rebels have had a bad losing streak as of late, and if this mission is as hard as it looks, I might have to consider a house rule of some kind.

I haven't played the mission, but it looks like you have it correct.

Something to note:

If two doors are open, the imperial can only claim 4 evacuees from the tile that has the door still closed. So I think the rebels should try to open one door on the first/second round and look at which trapped evacuee the IP first claims, then open the door to the other closed one(s). I also think the bonus white die would be crucial. Also, as always, performing as much crowd control during the first round as possible would be prudent. (Attack figures that you know you can defeat in one attack.)