Aaron,
I like what you have done.
I am working on the exact track fitment as you have it.
I am also working on some ideas to help with operational fun or "play value". They are tying the inner loop near the road between the two switches to the straight section. This will add direction reversing in both directions.
Next would be adding crossovers between the outer and the inner loop.
Those could be done at later time when you want more play value or operational variation to relieve the "I need something different" problem.
an area of concern is the TT. 20" spurs would be a minimum and 30" length if you were to add a roundhouse. Do you have the Atlas TT in hand?
Attached is a photo of another forum member's layout that I worked on with similar size limitations as yours. Used the Atlas Bear layout for ideas. His was a little wider. There was also the limitation of working with the track inventory that he had from his old layout. (GG and Ross) There was a small amount space at one end where the width could be increased. I was able to get a wye and a small loop in for a direction change.
Keep tinkering and tuning the concept that you have.
I think an all elevated line could work. The mountain top would be a base for the reason it would exist, such as a small mine or passenger station. The issue is that an elevated line can block the visuals that you are creating on the base level. Therefore, it has to be routed carefully.
