Beagle,
Almost correct though there seems to be a bit of misunderstanding regarding the FAA Temporary Airmans certificate. When you fist get the licence, they issue a Temporary Aimans Certificate, valid for 4 months which you can use to fly on until your (not temporary) Airmans certificate is delivered to you through the post. Now it is no longer temporary but full FAA PPL but restricted to use with ICAO licence (noted on back).
Your ICAO PPL must be valid in all respects for the FAA AC to be valid, including ratings. This excludes medical though IF you hold an FAA medical.
Ratings added on to the FAA PPL are marked 'US Test Passed', and are now no longer subject to the restrictions of the ICAO PPL (ie. I have no multi on my JAA licence, but have FAA multi).
For the FAA PPL AC to be valid, then you must comply with the relevant FARs which require a BFR to have taken place within the preceeding two years. Normally a club checkout will do, as long as the instructor notes that it was a BFR in your logbook.
Cheers
EA