Parrasailing and wave funners. I liked the parrasailing at Labadee. Ocho Rios do the river tubing through the lines. Great fun.At Georgetown do the stingray and snorkeling combo. Cozumel--Shop and stop at Senior Frogs bar snd clothsline.
We did that itinerary on Voyager last Jan....yes balcony is a great thing to have on this ship. Re weather, we had terrible weather 3 week of Jan, lots of rain and very cool temperatures but they told us this was unusual. Hopefully your weather will be wonderful.
I suggest Stingray City/Snorkel combo in Cayman and Dunns River Falls tour via boat in Jamaica.
My personal preference is always a balcony; however, if you are looking to save money on the cabin so you can spend it on an excursion, then the OV cabin will work. Also, you might find the nights on the ocean a little cool in Feb. so you may not spend as much time on your balcony. Apart from a balcony, you'll have access to everything else on the ship, just like the folks with the with the suites!
We went on this same itinary on Voyager 2 years ago - had a large port-hole ocean view on the 2nd deck as well. Was just fine for us.
In Labadee we did the sea kayaking and enjoyed it very much - - hiked up the Dunn's River Falls in Jamacia - quite and experience - you should check it out. Did a "submarine" type tour in Grand Caymen but we don't recommend it. Heard the snorkeling is beautiful in Grand Caymen and lots of folks enjoyed the stingrays..... Shop in Cozumel but don't pay their price for anything!