Using my Own custom character

Yes, you can create your own character in either Photoshop or Illustrator and dynamically link it to Character animator. There are several tutorials online to help you understand the process. To answer your second question, CH is designed to track your face as you tilt it from side to side. It can also respond to turning the head left and right and up and down, BUT you must create a new set of head and face drawings to match the new angles. Here's a list of useful video FAQ files: Adobe Character Animator Video FAQ (okaysamurai.com)