There should be the tour of the dig and such which does not give you access to the beach and or pools or anything but the dig and the public areas of the hotel and casino.
There should be a beach access which gives you access to all public areas, the beach and the pools, just not the waterpark.
Aquaventure gives you access to everything. You can go where you want when you want as long as you have this wristband (except near the rooms).
I think the option you choose really depends on what you want to do. If you just want to walk around and check the place out, do the digg tour and as long as you don't try to go in one of the pools or waterpark you should be OK. If you want to hang out at the pools or beach you will have to pay for that. We went over there years ago and didn't pay for anything, we walked through the digg, bought some stuff in the gift shop in the digg and walked all around the property until a security guard asked to see our room key, we told him we didn't have one and he said we have to stay in the main building than. So, we got to see what we wanted without spending a dime, but there are people around looking.