Ok, I have worked out most of the bugs save for two.
First is where when you replace bricks, you can't paint them with ColorFX (trust issue)
And the second is where you place bricks, paint them, undo the painting and the brick, then redo the brick and try to redo that painting, it doesn't work because it goes by object ID and everytime a brick is created, it has a new object ID.
I have an idea to get around the second one, but it's not working, and I think I know how to fix the first one.
I'm close to having this done.
I fixed the first one, had to set the bricks trust to 3.