I think the MOC is great, but I have to question the practicality of having a trading post with what equates to a drawbridge as the only entry point. Basically, anyone who wants to get into it has to be on the far side of the river. If you had set it back from the bank a bit further so that people could get in by walking around the front of the building, that would have been a little better, I think.
The interior is really nice though and I think your techniques are all very good. It's just that one layout problem that I'd suggest changing next time