wearwolf2500,
The idea behing grouping items is for texturing individual parts of the ship (lets say the fuselage), i.e. select faces on the same plane and group them as - group1 - for example, then texture them, move on to the next section, group and texture that until you have all your faces with a common texture, textured. Then you can simnply select all the faces and re-group them as fuselage. so long as you dont reselect them as a group and re-apply the texture by mistake, the same single texture can be used in all 3 planes (x,y,z). Save frequently....
Sure you could mirror a ship , but all you have then is 2 ships. Mirroring is normally used to make an exact duplicate of a component and place it in the exact opposite position. (Left/right, front/back up/down), many modellers as a standard practice will simply cut a model down the middle, and mirror it textures and all. The same applies to textures as applies to components and enables you to get 2 exactly the same halves as one single ship.
Hope this helps....
Harrier
Retreat[![! ---- I'm too badly messed up now[![!