Can you walk in on a Saturday and pay for water park only? If your not doing the hotel part

Yes

Yes but it's better to buy tickets ahead of time. Most of the time Saturday is a busiest and they do get sold out.

Yep!

Yes you can. You do not need to rent a room just to attend the water park. But purchase your ticket ahead of time online to save $5 per person on your visit.

Yes u can buy passes to waterpark without staying at hotel!

Yep, just did it last weekend