First, going in June or July is the best time to make a crossing, definitely the best time to go. Winds are almost always out of the east to south east in June and July and you might even get lucky and get winds of 5 knts or less out of the south. We have always crossed on our own, but have run into the Bahama flings groups before. These are particularly good if you are in a small center console. We carry a full suite of safety equipment including 2 epirbs, ocean liferaft, etc., but we do a couple of Bahamas trips a year solo and as far as the exumas as well as offshore runs with the boat between the Chesapeake and FL.
So for us, I consider the safety equipment mandatory and would not cross the gulf stream or run 50 miles offshore wihthout an epirb and life raft if going alone, but would do it without an epirb or liferaft with a Bahama Fling group. The worst case scenario is you have a problem in the middle of the gulf stream and drift north into the atlantic and then an epirb and liferaft could be very handy, at the same time on most days, especially weekends you will see several boats crossing between the Miami/West Palm inlets and West End/Lucaya or Bimini. My BoatUS towing pachage goes from the FL coast line to something like 100 miles out off the southern FL coastline.
Navigation is pretty easy if you very carefuly follow the GPS coordinates in the must have Steve Dodge guide to the Abacos or similar Explorer charts for Bimini and the Exumas. We use both the explorer charts and the guides routinely. If you venture off of the standard routes into anchorages or less traveled shallower areas, then caution and an ability to read the water become important. You should definitely have a backup GPS, in our previous boat I carried a backup handheld battery powered GPS with all coordinates pre-programmed but in our current boat there are two helms each programmed independently and we keep the hand held in the ditch bag with a hand held VHF and PLB.
We have two trips planned this year mid June to the Abacos and mid July to the Berrys and Exumas. Although we usually travel alone, you are welcome to cross with us if the dates work out.