I know modTer was probably the only reasonable choice but it looks really bland, and possibly could have used a smaller modTer set / been the same shape.
I suppose I could have used 32x or even 16x modter. However, consider the effect this would have on brickcount. As for looking bland, it is definitely my fault for not adding the smaller hull details and greebles (such as all the things on the vertical parts and the slightly thicker parts of the hull.
there are a few space vehicles out there
This right here is the problem with trying to make any sort of space-based TDM. The best Star Wars vehicles available don't even have proper collision, and they're too slow and not maneuverable enough. Other space vehicles have other problems, such as not having inverted controls somehow, or lacking weapons. Unfortunately, I don't know enough about modelling or Torquescript to make my own, but the lack of Star Wars vehicles is surprising given the relative popularity of Star Wars mods in other games.
As for the other part of your post, it would be cool to build an MC80 cruiser. However, there isn't a single straight line on the entire ship, so it'll be difficult. I'll definitely consider this, though, as well as building smaller ships such as Acclamator-class and Victory-class Star Destroyers, Tartan patrol cruisers, CR90 Corvettes, Nebulon-B Frigates, and MC40 Cruisers.