Hi, I just got back and as Dan said, most of the rides are ok, if not better than OK. He is right. Go and have fun. You will be surprised to see how many people of size are there!!! And, it was a lot easier then I expected.
On Space mountain, ask the CM where is the best seats for a person your size. I did that, and she directed me to certain rows-- when I went back to her and said "they look small" she said "trust me" - I did and it was fine.
Rocknroller coaster- hard to get in/out of, and the shoulder bar did not go as far down as some others, but it locked fine and the seat was also OK
Test track- pull the seatbelt all the way out and then sit- the belts are plenty big. More room on the end seats vs the middle
kali river- smaller seat belts- sit alone or go w/ someone significantly smaller ( a kid ) and you will be fine
Drew Carey seats: SMALLEST of all. I made it but it was a tight fit. The other theatre seats were better, but not great. You can do it but might not be that comfy.
ToT: pull the seat belt out b/4 sitting- seats are big enough
Splash mountain was the hardest fit for me. Uncomfortable and hard to get in/out, but again, I did it.
Hope this helps.
Rosie