If the Rebels just rush for the 5 nearest recruits and take them to the Exit tokens on the left, what can the Imperials do? Just ignore the Recruits and try to wound a Rebel or take out Luke? Since there's a one-round delay in getting the threat from the recruits, it seems like a bad idea to retrieve them.

If the rebels ignore the imperials, you need to defeat them. There is plenty of firepower. Defeating a figure will cause the recruit to be dropped, and it takes another action to pick up the recruit. But I also think that you should pick up a few well-chosen recruits to keep them out of the rebel hands. Either they need to defeat your stormtroopers or let them go. The later in the round you can do it, the better. Or early if you want to bait them spending actions.

Gideon and Luke combo well, and might keep Luke alive for a very long time (due to Luke's recover 2dmg), so with that combo I would leave Luke alone.

I think the only way to win as imperial with low threat level is when rebels ignore the imperial threat. If the rebels perform a good cleanup during the first round, they will probably sail to easy victory. (Unless you have a Nexu and it rolls a good defense a couple of times.)

A couple of playthroughs:

At threat level 2: https://boardgamegeek.com/article/19079944#19079944

At threat level 4: https://boardgamegeek.com/article/20116252#20116252

My difficulty was just catching up with them - the Elite STs seemed to be too far away to catch up and get any damage in.

My difficulty was just catching up with them - the Elite STs seemed to be too far away to catch up and get any damage in.

It's a tiny map, I don't see anywhere the Rebels can really go that you aren't going to be shooting them. The problem is you won't have enough time for the shooting to matter that much. Rebels should win this in 3 rounds, possibly 2 unless they have a weak team with no movement abilities.