you will probably take chicken exit at FJ. Hippogriff and dueling dragons are outdoor coasters so you can see if you want to skip or try. (I would guess skip). But don't miss the large hippogriff at the front of the ride. It's a good photo op and you can hear Hagrid's voice. Very cool for potter fans.
Try riding spiderman before going to potterland. If you can handle spiderman without getting sick or too scared then FJ is worth a try. It is in the dark and has more intense motion but it doesn't have huge drops or spinning. If you do try FJ I suggest getting a middle seat. The effects are less intense.
Things you can do in potterland with no fear/sickness:
castle walk through before FJ (this is one of the best lines ever) bring a camera with you
Ollivader's wand shop show...pretty fun and seems authentic
Honeyduke's/owl post/shopping
butterbeer
eat at 3 broomsticks
Go and have a magical time!!!