CPL Question - What does it all mean - Tips on use

1st Question: What are the differences in them? There is a Entry Level - Mid Level - "Pro" Series from Hoya. I opted for the Mid Level as I don't want Entry but don't feel the "Pro" is really needed. What am I missing out on by not getting the "Pro"

2nd: How does it actually work? IE It says I can select what rays are filtered? Are there adjustments?

3rd: I can basically kill off reflections on cars and get some great color from the sky and some extra contrast. That is the basic use?

First answer. In filters there are only the good ones (Hoya Pro 1, B+W MRC, Heliopn SH-PMC) and everything else. Get one of those 3 types and you're in good shape. Get anything else and it'll come back to bite you.

Second and third are really 1 question. Light waves vibrate in all directions. But when they're reflected off something (non-metallic), some of the vibration is reflected and some isn't. A polarizer lets you decide whether you want to see what was reflected or what was absorbed. If you choose the reflected part you get glare and reflections. If you choose to cancel out the glare, you get saturated colours, and can see through clear surfaces like glass or water that are reflecting. So, you can boost saturation of paint, sky, or whatever, or you can accentuate reflections. Your choice.

So basically cancel the order and go with the Pro Hoya?

*edit*

Wait I did order the pro.

Thanks for a more in depth answer.