Can't help too much with the happy hour question since we spend most of ours on our balcony with drinks in hand but that said, we've enjoyed the Greenhouse, and the Boat Bar.
For best fresh fish I'd suggest the Marigot marketplace very early in the morning since it's not that far from you, and as a back-up, Skipjacks in Simpson Bay has their own fish market though I haven't bought anything there. It always looks good when we go there for dinner. <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" /> <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" />