This is great info - thank you everyone. I think I got injecting silicone mixed up with breathing the fumes, so I'm straight on that now.
I think I will take Bogertophis advice and keep it simple, add a background and some branches for the BP to climb on and leave the rest as he has it now with two hides and a water bowl. Like you said, those foam sculptured sides look great, but I was worried about cleanliness.
I appreciate all the input - thanks guys!
Nick