Hello cheeky !
We were worried about this but needlessly as it turned out.You could quite happily manage without any cash at all as long as you have plastic !!
You need to make a conscious effort to spend some real belize dollars in local shops or tip local tour guides if you are at all concerned about seeing where your money goes towards local economies etc.
On the subject of tips-English folks like me have no problem with not tipping and then being billed for a service charge at the end because service in england is so bad that we dont need to tip anyway!.However we saw some Americans who felt this was a bit awkward and so they ended up tippng twice in fact.The staff dont lurk around in any way shape or form ,but of course they make a big point of getting to know you by name and remembering what you like to eat etc.If you are cynical you will question whether they want an additional gratuity ,but we didnt feel that because everyone seemed genuinely friendly .The tip policy is clearly mentioned when you book but feel free to reward your tour guides etc (they earn it !)
Trips etc-the normal way is to book for the next day when the concierge visits you at dinner-there is no pressure to do anything, but they will arrange most things the day before unless you know in advance and want to pre arrange.It isnt like places where they say "sorry ,we have no more spaces on this excursion".
Probably a good idea to read up on Mayan history and belief unless you dont want to visit any temples etc.Take really good walking boots unless you want to just sit on your deck.If you can find anything that deters sand flies then take loads of it-possibly the only down side to this hotel !
Also consider how you want to get there.We had chosen to fly in the charter they can provide from Belize city. In the event, due to fuel problems during the strike in January we went by road instead and really enjoyed the drive (albeit half asleep!)
If you can think of anything else let me know !