I can comment on SFB
. Early March should provide you with some decent spotting. I am not exactly sure when the charter season starts, but it is bound to be better than the current conditions. When you go, you should plan for a Friday or a Saturday. Those are the busiest days for the British charters.
Im not sure what you mean by "flow right". If you have more than several hours, you might want to hire a car. There are a couple of good spots around the airport, but beware, the Sanford Airport Authority isn't too keen on photographers hugging the fence. You may want to employ gorilla tactics when shooting.
I was there in early October and had no trouble what so ever. But, from what i hear however, that isn't the case for others.