I was out these days so I can reply only now...
about pcount....
when I started I was aiming for 12-15k tris, but I soon realized that I was going well over that limit:p
The actual pcount of the engines is iirc 7300/7500 triangles, so I evaluate that the final pcount will be between 17k and 20k triangles, without turretts.
That's high but not THAT high.
Also, I'll make an high poly lod1 (something like 10k tris) in order to reduce the lod0 range and help those with lower specs machines.
I'll use that new code from bob, but I wasn't aware of it and I don't have an idea of how it works. Anyway, if it just lets you define the visible range of specific subobjects, it'll be useful only for the "pure greebling"; it can't be used, for example, for most of the the pipeworks of the engines, where I'd need more a "subobjects' lod system", I mean the possibility to switch between low poly and high poly versions of a subobject depending by the distance of that subobject and not of the whole ship.
The engines btw are heavily optimized: I cutted more than 1k compared to my first version, with some minimal visual lossess but ****ing up the "cleaneness" of the geometry, I just hope that this will not cause shading or lightning weirdnesses. I also sliced the mesh in many submodels to reduce the pcount, some of them are intersecting and I hope that this won't cause problems.
Side note: the horizontal engine is meant to be blocky, alsthought it turned out smoothy in the render.