I dont think air circulation will be a problem. I think the 14 inches wide will be more of an issue later down the road. As for decorations...keep it simple. I used newspaper as substrate, easy to change out and keep clean. I used a basking rock, and a nice branch, and thats about it. Lighting height all depends on temps at the basking spot, you want to see 100-110 degrees, any height that gives you that at the basking spot is good. As for the uvb height, if its a repti-sun 10.0 20 inches is the max distance, reptisun 5.0 i think is like 16. those are very important, i keep mine within 12 inches of the branch, that way the get enough uv's.