Hi Nacho13,
great to hear your looking to relocate to Jamaica. I am looking to move to the island next year as well but I will be in the Ochi Rios area.
The security is ok, however your better off finding other expats in Montego bay who have lived there and can show you the ropes. If your not looking for trouble you will be fine as Jamaicans are very friendly and out going people.
Every area/parish in Jamaica has its uniqueness so you need to know the do's and the don'ts.
Good luck! hopefully we can meet next yr