8 x 12 layout feedback

I attached an image of what I'm currently planning. Track will be Menards O, with possible Ross Switches. As for the design, I have a 8' deep x 12' wide space, with the front and left side completely open. Back (top of diagram), and right wall are immovable. I was shooting for something that could support 3 independently controlled trains in conventional, with maybe one section eventually supporting the LionChief trains with a fixed supply voltage. I also wanted something with a second level.

All that being said, here's what I've worked out. The yellow line is my grade, and blue is the second level. Grade is steepish, and will limit some things I can run, but only having to raise 6" over 125" should be ok for my needs, since I'm going for more nostalgic factor and less prototypical.  I just wanted another set of eyes on this for suggestions of improvement, or things to watch out for.  It'll help to expand my ever growing wisdom.  Thanks!