Very nice and interesting ship design
I'm afraid I can't help with the errors.. I'm using blender myself which does not seem to have all those fancy export options so I'm clueless as to what the problem might be.
I do remember hearing that size of textures and number of polygons should not be a problem for the game engine, it would just slow down the game, but it wouldn't produce errors.
(David gervais once said he had a model of 30.000 polygons he got of the internet which worked fine in starfury)