Don,
January VB should be out by mid December, if your PD is going to be current you can always change your rerun flights to come back and apply for AOS.
Q1) Yes, on valid non-immigrant status (when you come back have to enter into US using a valid VISA).
Q2) Don't know at this point!
Q3) This shouldn't take more than a week.
Q4) Yes, strongly advise to apply together.