Hi Nickers, this is a very interesting project and I look forward to seeing the finished thing, I was flattered at your compliment many thanks. If you need any help just drop me a line.
The white and purple colour reminds me a lot of the palace so you could add parts from that without any problem, I think it will look very nice like that, very American in colouring. They seam to have loads of Gothic / Victorian houses in grand shapes and colours.
I can understand why you've had to glue the base I had similar trouble with a smaller house I did where the front extended outwards as there's no way to clip a cut down floor to it. My current house is 13 sections across but being almost level the clips will keep it together, but it does need two people to lift it.
I had the same trouble when I first started spray painting - ignore the can if you need to do a second coat put it on about 15mins later otherwise your looking at more like a month or two to repaint it. If you end up with a small damaged area try cleaning the plastic down to the original with turps / white spirit and mask off that area to respray, it might just save the wall.
You did a good job with your attic conversion very nicely done!
Well good luck with the rest, it's coming on very nicely.