#1
When I play some songs my thumb is lower than the middle of the guitar and its not pointing up its pointing to the side.
#4
You should try to learn how to keep your thumb behind the neck in the area between your four fingers. This means not gluing your thumb to a particular spot and just moving your fingers around but lifting your thumb from the neck and repositioning your whole hand in relation to the fingerboard position. A lot of beginners squeeze the neck between their thumb and fingers and it's not necessary to use a lot of force. This will also help increase you range as you're not pinned to spot on the neck.
Moving on.....
#6
I backwards i use my thumb a lot so i been trying to get use to doing thumb barre chords O_o

Guitar : Fender CIJ Mustang and a Telecaster
Amp : 76 fender champ
Pedals : BBE green screamer, Big muff, Ibanez LU20 Pedal Tuner, boss loop pedal