very simple interiors
Yes. VERY simple. But given the nature of the ship, putting much more into the interiors would be a complete waste. It's not like you're actually going to be taking a walk in the darn thing. IMO, what will/probably should take up a lot more of your poly/tri-count, are whatever characters you'll have manning the consoles in the cockpit.
Edit: What ARE the polycounts of most of the bridge set characters, anyway? Only a hundred or so at most, eh?