1.ABF, (grapes) isn't a bad rating. It is much better than ABH.
2.You deploy, when the ship deploys. You will likely make 1-2 cruises, plus work ups. You will have a sea/shore rotation over your 20yrs.
3.You will live on the boat if you aren't married. If you are you will only be on the boat on your duty days. You can get a place off the boat with your own money if you are single. Many guys will share a small apartment for when they don't have duty.
4.At sea you have night check/day check. 7/12 at sea there isn't any place to go so you work everyday. What else would you do? You rating is good because in port you don't have much to do that the duty section can't handle. A guy working in supply may have it easy while at sea, but in port they are loading, and unloading the cargo.
If you don't want to be on a boat, why did you join the navy? It really isn't bad. You will work 10-20 days in a row, then pull in and have 3,4,5 days to see at new country.
To add to what was said above. You may hit the shower after working 12hrs, and a GQ happens, well so much for sleep, but it really isn't bad. You can FORGET getting shore duty on this 1st enlistment.