^There are plenty of noodle things to eat without fish, so don't worry! Fuji-Q has some great veggie foods and noodles in the "stadium" food court.
As for Disney, look on their website to see how crowded the parks are supposed to be those days (I think it was in the Park Hours section). If you want to end with it go for it, even with psycho crowds the park really knows how to deal with it and they do a great job!
I would stick with the schedule you have now, you're not really going to be 'near' any other parks that would be anything but a credit run, and I agree that you want to somewhat take it easy.