That new plan looks much better, I was going to have to agree with Jason and you were asking for problems with that nasty track arrangement. Maybe a few small issues here and there, but nothing that shouldn't be able to smooth out when you actually do the work. Most important thing is to remember to just sight down the rails as you lay them and if it looks smooth you should be good to go. As someone said the tight curves are ok in this type of application but they still need to be smooth.
As far as the plan itself, I think it looks promising and will provide a lot of activity!
Mike