This board is mainly about the Universal Orlando resort. But, by looking at Wikipedia, I think I can give you some help with the rides common to both Parks. I'm also Pooh sized (or Shrek Sized in Universal terms). I'm 6'4" tall 320lbs and about a 45" waist. Of the common rides, Forbidden Journey gave me the most trouble. I just fit with some ride op help. Some was my size but also my height. I had to get in pull the restraint down, then slough down just a little to get the last click because of my shoulders/chest. Forbidden Journey originally opened in the U.S. with more restrictive restraints, The outside seats were modified tp allow a little more room. I don't know if Japan has the modified seats or not.
Back to the Future wasn't a problem. If you're tall, you'll want to try to get the front seat of the car for a little more leg room.
Jurassic park has a single lap bar for everyone in the row. So, others in the row may want to have the lap bar down farther than you want to or can.
Spiderman has fairly accommodating seats. I've had no problems with it.
Jaws is a big bench seat and not a problem.
Shrek 4d and Terminator 2 3d for motion seat theaters. If you can sit in regular theater seats you'll be fine here.