well, to begin with, you could, to add more of a battle feel to them, actually destroy some of the buildings, like the high-rise, just cut out a couple of the windows with a kitchen knife, a serrated blade works best, with the bunker, add a few more rust effects around more than under a few of the weapons, like on the edges of the doors, dab a bit of a bestial brown mixed with elf gray onto the edges, or drybrush it on. The cottage looks somewhat comical, nothing against it at all, it's just different than what I've seen put together with the heart on the roof and all, It looks good though. The small building could do with some washes around the bricks or maybe some kind of imperial graffiti or something on a side wall. It all looks pretty good though, I'm very much a to-scale guy myself, so I like to make sure that whatever I'm building, their models can easily go through doorways and such.
Hey those are all pretty cool. I really like the bunker thing =)