Newbie Questions on vinyl, tubes, and superior sound

[SynergySystem]

Lately ive become very intrested in vinyl. And i have alot of
questions that have made me rethink not only CDs but my listening
equipment as a whole. First off, ive heard that vinyl while maybe not
technically superior, it is emotionally. Ive heard it said that since
vinyl is not digitally compressed it has a fuller warmer sound. That cd
is colder and more exacting. Im unsure though, i did have a turntable
when i was a teenager but had poor quality speakers(whose grilles
werent even removable). I did like the sound of the turntable though. A
few questions on vinyl first.

1)Is there a diffrence in sound quality between a 12" vinyl or 7" vinyl, or just size?

2)What diffrence does the speed of the LP make(you know 33 rpm etc)?

3)Do you feel you need tubes to fully take advantage of the Vinyl sound?

4) What are some pros and cons of switching to vinyl?

Thanks for your time and patience []

Post Script: I asked this on 2 channel and think it is better suited here.