It looks like it could be a lot of fun. Build it and have a blast.
The only thing I can see is that you'll be working directly from the yard a lot, moving 1 car at a time from there to the various industries, because there are 2 critical switchback stubs that can hold the SW and one car. It appears that you will be able to move 2 cars at a time from the main to the yard.
If you'd rather move a whole cut to the main or runaround area and then work from that, you might extend the LR stub a foot or so, or replace the existing yard with industry tracks and perhaps add another right-facing stub track to make that area into a yard.
As it is now, though, it looks fine, and you can always make whatever changes you like later. Go for it and have a good time.
Here's an idea, too: When you're done, and it's all working well, take it to a train show, so the public can see that trains are good for more than orbiting. Somebody did this at our local show, and it's amazing how much attention is drawn, even with the switching done at very slow scale speeds.