Many of them don't have a bump? Well that makes ships lower quality a lot of times. It's not needed, but it makes a model MUCH better looking. Take a look at some ingame ships like the ISD. They have bump maps. They look very nice indeed. Some of the ingame models don't have bump maps? Well they're either in such a position where they won't be noticed or it may be that it wouldn't look correct to have a bump map their, like sometimes on skin. For your HP prob, go look at swgbex's tut. Go to one object and use attach.