My thumb is moving around when I switch chords. Ex. In G chord my finger is vertical on the neck, then when I switch to C chord my thumb is horizontal causing my fingers to mute certain strings.
for the most part, yeah
I'm having troubles with the C Chord, my first finger is muting the e string.
Just a note, your thumb isn't really supposed to be horizontal. It restricts your playing a bit.
Yeah, if you can try to avoid holding the neck as if you were holding a baseball bat. Other then that it's pretty much fair game.