1. It is possible to dream bout lucid dreaming without actually being lucid, though it is unlikely
2. I do RCs at random times as well. I've never been able to do a RC in my dreams though. When I had my first LD (I've only had one so far, I'm also new) I just suddenly realized that i was dreaming.
3. Thinking about LD before sleeping won't prevent you from remembering dreams. Thinking about it too much when you wake up might, as it may make you forget about the dream you had just a sec ago which you would usually remember
4. I don't think it is possible to be stuck in SP forever. You can get stuck in it for half an hour or so. I've got no experience with SP, so I'm not the one to answer this question