#1
are actually in western music?
how many different modes are they and what are they called?
#2
Depends how you define "scale".
The short answer is: A lot
The short and correct answer is: It doesn't really matter

The vast majority of scales scales and modes that you could construct from the chromatic scale aren't even remotely harmonically stable, and are useless for constructing chord progressions. All of them could be described as alterations to the major/minor scales anyway, making naming each and every one of them just pointless.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.
#3
There are seven modes of the major scale, which are the most often used by rock musicians. Of course, there are the modes of the harmonic and melodic minor scales as well, which are used less often.

But as mentioned, there are theoretically hundreds of possible scales, even just based off of the 12 notes of the chromatic scale. Most of them wouldn't sound too hot though.
no
#4
Pretty much you can break it down to every scale is based on alterations to one of four scales 1. Minor Pentatonic 2.Whole Tone 3.Major 4.Diminished. All other scales are built on modes and/or alterations of these.