Beginner-Character deform not so smooth

Hey again! I’m gonna be on this forum a bit more regularly now that I’m going full out! Anyway, I have some more rigging problems that I need some tutelage with (Cause I know you guys are awesome). Blender file in reply!

Pain 1

Similar to my last problem with the head, moving the shoulder armatures creates an ugly deformation. Would love it if you guys could tell me how to fix these in future!

Pain 2

2 things here:

  1. The connected armatures rotate faster than their assigned weights when the parent is moving
  2. There’s an obvious zig-zag to the character for some reason!
    Pain 3

    How do I link that upper-body bone to the two shoulder blades? (I have no idea what’s going on with the shadows)

Thanks guys. If there’s anything else I can improve on or make look better let me know!!! I’m going to be figuring out how to shade next so there may be future questions :(. Thanks again!

Blender file :slight_smile: Current iteration.blend (163 KB)

Edit: Pain 1 SOLVED. Used subdivision surface modifier!