1. I agree with what moSh said... I've never tried listening to such a recording, but it could potentially help. I've also sometimes heard something in my sleep that translated into part of my dream. So, it's worth a try!

2. It depends. If you're watching videos about lucid dreaming that could maybe seep into your subconscious and be beneficial to your progress. However, in general it's not the best idea to be staring at a bright screen right before going to sleep. Seeing light tricks your brain into thinking it's daytime, which can make it harder to fall asleep in the first place.

3. As far as I'm aware, you can do just about anything you want in a lucid dream. So, sure. Why not?

4. Yes, I definitely think so. Reading about other people's experiences will give you more knowledge and help you find out what to expect once you're in a lucid dream.