Welcome to Dream Views!

You have some good questions there, and I think you'll like the answers! First of all, I'm not sure what FILD is, I think you meant to type DILD based on your account. When you started floating, I think you may have inadvertently changed your state of consciousness. I know that some activities like floating, riding an elevator, or anything that moves you up or down can have that effect. Some people use it for inducing OBEs and astral travel. If it becomes an issue, just resolve not to fly around until you become more acclimated to your dream environment, that should help.

As for the "reality" of a lucid dream, strictly speaking, it is entirely subjective. Fortunately, the human mind is unable to discern objective reality from subjective reality. In the waking state, your brain uses nuero-chemical inhibitors to prevent you from experiencing your memories as though they were happening there and then. When you're dreaming, however, those inhibitors are blocked by yet another inhibitor, so you can't tell that you're dreaming, hence the necessity of RCs. As you become more accustomed to lucidity, you'll find that the experiences feel just as "real" as waking life. You recall every color, sensation, thought, event, and emotion. This is why lucid dreaming is so inviting; you actually have the opportunity to experience things that you could never experience in waking life. I wish you good luck in your endeavors. You'll find that this community is the best place to be for people like yourself. Enjoy your stay!