I'm 29 and recently had two shoulder subluxations in judo, and am still training combat sports, so I'll you what I've been through.
My first dislocation was in a judo tournament in January and I took 2 months off, doing what I thought was good shoulder rehab (after reading a lot of articles here on T-Nation) but then after 8 weeks (mid march), I went back to judo and dislocated it during the very first class. I went to my doctor and he sent me to get a MRI of my shoulder and then consult with an orthopedic surgeon who specializes in shoulders. The MRI showed a torn labrum and a 30% torn rotator cuff ligament.
Given my desire to do judo, as well as kendo and submission grappling, the doctor told me that I have an 80% chance of further dislocation. The danger there is that right now I only have soft tissue damage, but as dislocations keep occurring there is a danger of the bones abrading. They can always fix soft tissue with surgery, but can't do anything about bone that is missing. After surgery I would have a 5% chance of reinjury, but the recovery sucks, and I want to keep training, so I've opted for 6 weeks of PT instead to try to really strengthen things properly.
My last dislocation was about 8 weeks ago now, and I'm weight training again, as well as grappling. (Judo grappling is just like BJJ so you can consider them the same) The grappling is actually surprisingly easy on my shoulder with the one exception of ude-garami (or kimura if you watch ufc) on my injured side. I've just learned to tap fast if it's sunk and not try to fight that side. I'm also doing kendo, which is very shoulder intensive but so far, aside from being stiff the day after, things are going well.
I plan on skipping judo this summer, and not trying it again until I really feel that I'm 100%. To me 100% means zero pain on external rotations, or no pain when grabbing the squat bar. It means not feeling that twinge when I bench, and being able to sleep on my side again. I've been icing the shoulder with a special wrap that I bought at the sports store right after class, because I've noticed that when I'm warmed up and loose, I barely feel any difference between healthy and bad shoulder, but if I don't ice before the pain sets in, the pain is much worse. Also, I'm taking 800mg ibuprofen twice a day and glucosamine as well as lots of fish oil.
I'm certain that you can train in combat sports if you take it easy, and honestly BJJ or grappling would be a pretty good choice. Make sure to get an MRI though, because your damage could be worse than mine.