Just my take on Logging Landings....
First off, your logbook is YOUR logbook. Make any notes that you feel important, or "milestones".
Second, If I am a Required Crewmember, I log it. If I am am teaching a student pilot, I am required. If the student already has soloed, he cannot carry passengers. Therefore, the CFI is not a passenger, but a required crewmember.
When flying an RJ or Airbus, you are a required crewmember. I log them all. With 16,000 + hours, nobody has EVER questioned me on "how many landings do you have?".
As far as currency goes, if you are a flight instructor, this should not even be an issue.....providing you keep busy.