Lifestyle depends on where you live (Island). Living on a Rock isn't easy, you are home most nights, but its the same bars, same clubs, same people. One can stand, while some cant.
Your in the Caribbean, so Rum and Alcohol is cheap 2-3 USD for a beer. Alcohol and coke 5-7 USD. Food, depends on how you eat. Eating out is about 40 USD a day. If you cook, then spends about 150 USD a week in groceries. Rent is from 600>.
As I said, it all depends on what Island you get hired to work on, they pay, the diet you choose, etc.
Get an interview first then ask questions pertaining to the job and Island.
All your other questions, as I said depends on where you work.