Awesome combination of
GW kits and plasticcard! It's a nice way to get large builds, but still keep that technogothic look we all love.
One thought on basing, though. Increasingly, I'm reducing the size of the bases on my terrain as far as possible, particularly on buildings. The reason for this is to keep the terrain from becoming too locked in to one tileset.
When I build my jungle cathedral, I went all in, and built bases with lots of theme:
But this means that it looks super out of place on anything but a jungle board.
So now, I try to make the the piece as robust as possible, so it can fit onto any board:
Also, consider spattering and darkenning effects around the lower area of ruins, and such. This helps them merge into the battlefield, too.
Otherwise, great work, good luck, and keep up your enthusiasm by playing some games with your terrain too!