Is there a height requirement for any of the rides?

Yes, but there are still lots of things to do if you don't meet some of the requirements.

Yes

Yes is necessary to the aquatic rides

However they do have a kid's area with kid only slides

For all the rides there is a small sign which shows how tall you have to be to ride, this is also true in the other two parks: Islands of Adventure and Florida Studios.

Yes, and it doesnt take much height to fit the requirement, now there is barely a height requirement, except weight is a very important check, riders who are too heavy together must ride in separation from one another, usually to pass the weight requirement, to get on most. Rides you should be anywhere from 100-200 lbs, exceeding this may cause you to wait longer to get on the ride