The Rhone is best when you dive, but it is actually a great snorkel stop too - you can actually see a LOT more then I would have ever expected by snorkeling. One friend of ours even did the swim through of the propeller - one that we normally do when diving!

As far as the rest of it, I'd probably do 1 night at Virgin Gorda. We almost always do 2 but with 5 nights, it would be less running around to do just 1 night.. Here's one option that would fit in all your stops, plus add one more and make a shorter leg Sunday.

FRI (6/16): ARRIVE, then stay on Tortola
SAT (6/17): Tortola > Rhone > Cooper (backup Marina Cay)
SUN (6/18): Cooper > Virgin Gorda (get there as early as possible, rent car explore the baths..etc)
MON (6/19): Virgin Gorda > Jost Van Dyke
TUE (6/20): Jost Van Dyke > Norman (The Indians / The Caves on the way)
WED (6/21): Norman > Tortoal