First, is a single anchor at 5-1 scope for non-storm conditions (winds below 20 knots) adequate for over night on the sand bottoms normally encountered in the Bahamas?
If it blew really really hard I would use 7:1 scope. 5/8 chain is massive overkill and nothing wrong with it. Actually 1/2 inch would be more like regular overkill and 3/8 would be only OK
Attaching the bridle is a good idea but I would not go all the way back to midship cleats
. If you had a pair of bow chocks more forward I think it work better. It's not easy to make the attachment work well that far back. It might twist as well.
The bridle will increase your scope a tad by decreasing the sharpness of the angle plus provide two places to carry the load. With that much hardware
in the water
(about 150 ft @ 3.8 lbs / ft plus 45 = 650 lbs!) Pray your windlass lasts and the batteries don't go dead or you will be planted. Securing it all from one cleat is starting to be a lot. Safe working load on a heavy windlass would be about 700 lbs.
I would say you should be anchored well. The bigger problem would be those less well anchored headed for you. Adding the other anchors with this setup would really not be that important. If you really needed the other anchors you best be some place else.