Paul,
I created your room using SCARM which is free with a limited number of track sections. It will allow you to play with this room. You didn't indicate which way the doors swing. For now I'll assume that it is inward.
I feel that a mid-40s inch height is ideal for all but the youngest kids. Since you are getting back in after 19 years I expect that children are older or have moved out.
You'll want to use the largest diameter track that you can. This will let you run all the equipment that you want, and it looks better. Also I feel you should use sectional curves over bending your own. Small radius curves are a problem.
Jan