Not so sure that's a good idea dpending on spawn points by creating out of bounds. If the Imps only start location is from the ships then funneling them by creating an out of bounds west and south gives the Rebs a huge advantage.
I don't see it as restrictive. If he did something like this:

The Empire would still have a wide area to maneuver in.
But of course this is just musing. I don't want to hijack Tom's map.
Re the map itself, all those walls are going to make this a very interesting infantry scenario.
"One of the bitches actually gave birth while she was attacking, and her puppies joined in on the carnage."
--the awesomeness that is Boatmurdered.