3] Tevas are fine--don't bring sneakers just for this excursion. Tanisha tours was great.
4] If you can really stay longer, do it now. You will not regret .
5] I like my money in $20 bills--easier to spend on small stuff--often change can be a hassle.
6] Yes, they should have floaties.
A small flashlight is key, as a matter of fact, it makes a good keychain--at any outdoor store or Kmart