You are coming at a variable time indeed. It could be nice or it could be nasty. More likely to be nasty at this time of year than at others.
Mosquitoes hatched a couple of days ago and they are fierce at my house, but I am outside town and perhaps more affected due to foliage. Prior to this hatching, the entire year was almost bug-free.
There will still be activities on the island, but if you are one of the "perfect vacation" seekers you may end up grumpy.

If you have found a hotel for your group, the front desk should be well versed in the list of businesses that are open. I noticed that Mesa Cafe, El Foggon, Road-Kill and Fidos appeared open in town. North of town the Lazy Croc was open yesterday, and the new restaurant at Grande Caribe called "Rain" is also open for business. Pretty sure Portofino stays open all season as well.

Rains yesterday flooded the road just at the north side of the bridge (passable but not nice), but traveling about in town was not a problem at all.