Hi,

I'il try to answer some questions of yours.

0. You might be making yourself somewhat subconsciously excited or hyped for upcoming lucid dream attempt. I used to have problems to fall asleep when i knew that big halloween update will be released at morning for Team Fortress 2,
I wasn't excited too much yet i had problems with falling asleep still

You can try some mix of mantra and relaxation techniques.
Tell yourself after setting up alarm that it's nothing big and your just going to be dreaming like always since being child. Dreaming and nothing more n' nothing less.

1. We tend to dream about lucid dreams related stuf when we are excited for them. Similiar can be getting wet dreams out of slight hornyness, i guess?
Mental Prep here should do the job. During waking life you'd need to train yourself to do reality check or awareness tech whenever you talk about lucid dreaming with somebody, and have confidence (Or hope) that habit will bleed into the dreams after some time.

2. It might be not mere excitement, it could be strong fear aswell or it might be just end of your rem cycle. Some people might get lucid or conscious when their rem cycle is near end. If your one of them DEILD Technique might be helpful here. Dream Re-Entry might extend Rem Phase.

3. That's the point, even if your comfortable you should try to question your reality. Dreams are based on waking life experience, even if dreams are weird or impossible to certain degree they are based on our memories. Be it either reading Tolkien's book or doing marathon of all Harry Potter movies aswell it could be simply your daily life

Hopefully i've helped somewhat.
If you have more questions i can try to answer them
- Cheers