Hi mickyjo, I don't know about St Lucia as I have never been but I have been to Jamaica went two years ago for my 50th Birthday as I had always wanted to go and I was not disappointed. Yes there chatter about Jamaica not being safe, but the same could be said of Egypt.
I will say that if you are a smoker you may be approached when you land and come through customs etc and then go to the coaches, if you want to 'smoke the reefer' - I don't smoke but my son (25) is a smoker and he lit up a cig, after 10 hours flying with no fags he was ready to eat his armpits. So he was approached but firmly said no and he was left alone, I did not get offered anything anywhere.
I did leave the complex and went across the busy street to a small shaopping mall, some of the guests fretted about the locals, but I had issues and went over there once with son and couple of times on my own.Also did some trips which were the normal tourist ones.
I probably would not go to Kingston on my own, but I would happy to go back to Jamaica on holiday and plan to do so on my own.
Hope that helps