1. Sony hasn't really said a whole lot about the camera yet. I think the only "game" confirmed to support it so far is Play Room which started as a tech demo, but is now going to come pre - installed on every PS4. There's a couple videos of it in this thread. I think it'll do other things like allow you to video chat and upload your picture to your profile but not sure what else yet. Only time will tell if it'll be worth it or not though
2. R* has no plans to bring GTA V to next generation consoles yet. They've talked about GTA: Online coming to PS4, but not necessarily GTA V. If it does happen it might not be for a while
3. Check your local gamestops or amazon. I would think Sony would be taking them still but don't quote me. I'm in the same boat as you with the Watch Dogs bundle, that's the one I pre ordered. Not a big fan of FPS' either although ill probably still get Battlefield because my boy plays it, and Destiny looks too good to pass up