Uh. the segment idea... well, all the units so far would fit nicely against a wall. you could create them as a segment that could be placed on top of an existing segment (like the way you can place corner segments).
The main benefit would be that they would be loaded as part of the map, which would aid in culling, and would mean they were added to the universe.dbo so load times would be faster. Sure they would be useful as entities, but making buttercutter has taught me alot about how useful and flexible the segment system is.
Henry, if this comes out free, I'll download and make a segment version for you.
Feedback wise..
I like the newest screenshot, although the tiles on the back wall look very large, and I'm not sure they'll tile very nicely if you place 2 next to each other, I mean, shouldn't those tiles be about the same size as one of the cooker's hobs?
Other than that, I like it alot.
Good work, especially consdering how long you've been modelling for.