Just from looking at the screen shots, it looks decent enough - some interesting blind spots (especially in the bottom - could be difficult to clear enemies in there without them invading the airlock), maybe I'd remove one of the top discharge coils to make another blind / dead spot there but that's up to you (discharge coils use a lot of power - having two up there could drain the capacitors quite quickly). I suspect the bridge will get flooded and invaded quite often, better be prepared for that! On my custom subs the bridge is usually in the middle of the sub somewhere (still gets flooded, but then I tend to run small scout subs).