Hi Lauren,
1) It's not Java, it's Javascript and it will be the same when you deactivate it on your computer. (so it doesn't matter that it's an iPhone)
2) And yes, that's a problem! Maybe (but I don't think so) using custom CSS could be a solution when you add a "display: none" to the fields that you don't need. But I'm not sure if hidden fields have their own css class/div?
Best regards
Steffen