You should just miss the spring break stuff. We were there last year around the 22th thru the 26th - packed. Still fun though. No worries on rain typically - short sleeves & bring jackets & sweatshirts to layer for evening. Pants for evening too - shorts too chilly (and this is from Colorado people.) Admittedly I'm a little colder than other people, but everyone in our group put on extra clothing when we were out of the sun. I would highly doubt you'll have any waits longer than 20 minutes. 10-15 minutes should be just about normal.