The sink is in. I put double stick tape over the back, put it in place, and held it there while I screwed it in from the back side. Worked like a charm. The part of the exterior with screw heads sticking out is going to be covered by a piece of foam core board. The toilet is glued to the wall and floor. I stuck some scrap foam core board in the back of the toilet and pushed a T pin into it to act as the flush handle.
I forgot to take a picture of the plumbing when I was done, but since the broom closet isn't attached yet I can sneak the camera in through where the closet door is going to be.
I'm glad I experimented with it, but don't think I'll bother making plumbing again unless I've got a very, very good reason.
Now....how much of this will be seen in the finished build?
View from the closest side window, which will have a bookcase table in the way later...
View from the furthest side window...
View from the bathroom window...
I didn't even bother putting the faucets on the sink because no one will see them; I'll save them for another project.
The second problem with taping in thae wallpaper has shown itself. Every time my arm brushes the top edge of the wall it disturbs the paper.
It's also lifting where I wrapped it around the edge of the closet door opening.
I've got some gel medium on the way, once it's here I'll fix the edge issues.