Best of luck; that's some pretty nice trail, at least the bits that I've seen. Doing it with your son sounds like a great approach.

I think that walking or hitching into town is a good decision too; unless you were lucky enough to have truly dedicated support people, coordination is such a pain. I didn't know there was a shuttle into Leadville; I didn't find that to be too hard to hitchhike to or from (about 9 miles off trail at Tennessee pass). I didn't go off trail to see the Mountain division training area in there; don't know if it's worth doing or not.

Twin lakes: do you plan to walk the road or short-cut there? I got a bit wet doing the shortcut (south of Twin lakes), but it worked out not too bad. On the off chance you don't already know, the cafe is no longer in operation but the little store is now stocking a bit more food to compensate.

Have a great time out there!