Do they have a season pass option (or anything similar; year pass, weekend pass, etc.)?

They do

I do believe so.

Yes

Yes they do have yearly passes

They have 1 month, 3 month and annual pass options for individuals and families.

I'm not for sure but they tell u just about everything on their site from what i remember. I don't believe their are any season, year, or weekend passes, but it's been awhile since I been on or read their site, sorry. I have been told it's best for u to get 1 of the motel/hotel rooms that are associated with the water park because u basically can go for 2 days. U can go the day u are checking in, but also next day before checking out as well... Sorry that I couldn't help more, sir.