"Offshore I'm looking for: 1. sailfish 2.dolfin (or anything tasty) maybe white marlin. I thought fishing for sailfish in April was excellent...true/false?"
If your expectations are to catch pelagic fish, you are most likely to be disappointed. Belize has very good flats fishing for bonefish, permit and tarpon. And, you should have no problem catching snapper and grouper. But to hire a guide and spend the money expecting to catch billfish etc, you will find that to be far less predictable.
I hate to see people spend their money with expectations that are not realistic and then be disappointed. I would be interested in knowing where you got the impression that sailfishing in Belize was excellent. I would not rate Belize as a billfishing destination compared to many other places where it is much more predictable.
Do your research, don't come with unrealistic expectations and enjoy the kinds of fishing Belize has to offer.