036 crossovers between mainlines make a pretty serious S-curve, which may cause problems. Even if you're not using 072 curves, you should use 072 switches for your crossovers for smoother transitions. Numbered switches are even better as they eliminate the S-curve, but Fastrack tops out at 072.
Here's my 9x12 Fastrack layout (almost the same space as yours). Two mainlines with reversing options, outer 060 inner 048, 5 sidings each capable of storing 2-3 scale freight cars, and an Atlas 24" TT with 4 whisker tracks. It features the lift-out extended truss bridge for access to the center or I can duck under it. I also have 3x 100" storage sidings on a shelf behind the layout.
The lift-out bridge is at its lowest setting (about 3" above the tabletop) and I'm using WS 2% incline sets for the grades up to the bridge. Light green track sections are grades.
Note that this is in my garage where I have access from the front (where the bridge is) and oth sides. If you were trying to fit this into a 9x12 room, you may have some access issues.
