Belize - Details
Negative to all your questions, but I charted out of San Pedro in Belize last March from TMM.
The word I got was that crimes against tourists were dealt with severely.
I encountered a number of locals is situations where I was vulnerable - no problem. I visited a guy in a fish camp, a crew on a native fishing boat (two different exploits), and a guy in a canoe flagging me down. All were memorable and friendly.
You will enjoy Belize. I liked it better than the BVI.
I would suggest that you not worry about where to go and anything else. Just follow the wind and you will have a good time! TMM knows their stuff and will be your best source of info.