Couple things I'd like to see, both could be done once the bsp is constructed.
First since any angle turrets are now possible once again. How about optional (assume straight up or down otherwise) three light points for each turret, named: CENTER, TOP, FRONT. Have these attached to the base of the turret, actual location relative to the model is irreleveant. From those you should be able to generate a top and front vector, which needs to be added to the subobjects properties. I'm sure theres quite a few guys that'll love this feature, myself included.
Second, I mentioned this long time ago. But could it be possible to have a second style for turrets.
instead of:
turret01
base
turret01-arm
arms
turret01-fp-01
turret01-fp-02
turret01-fp-03
have something much simplier:
turret01
base
Barrel
arms
fp-01
fp-02
fp-03
that way when you need to place a dozen or so turrets of the same style (copy and duplicate), you don't have to go through the laborish task of renumbering everything.