Hi Ryan,
Yes I agree with you, the PMBOK doesn't really list the steps to handle a change request. Below are the steps I got from Rita Mulcahy's book (Rita v9, pg 161):
A change request is submitted:
1. Evaluate the impact
2. Identify options
3. Get the change request approved internally
4. Get customer buy-in (if required)
That should answer your #1 and #2 questions. As for the last one, I think a verbal change request should be recorded for tracking purpose (ex. via a change request form or PMIS).
Hope this helps,
Joe