If you are flying with someone who has not met the 90 day currency requirements then you must be flying in your capacity as flying instructor and, therefore, operating as captain (P1). The other guy must be PUT if he is to be able to count the flight for the 90 day currency,and must be the handling pilot for take off and landing. He cannot be P1s in this circumstance, although I do know that lots of people would incorrectly log this circumstance as P1s. Just the same, the bi-annual instructional flight for the SEP revalidation should also, strictly, be logged as PUT by the "student". It doesn't have so much to do with who's touching the controls - most of the instructional flights I give are done by the student under my supervision, but I can never let the student log P1s because I'm not an examiner and so none of them are flight tests.
I can't comment on your club's (sensible) rule about instructor checkouts on type - that, presumably, is for your club CFI to interpret. Wether or not this flight would be anything to do with the club at which you normally instruct is for you to interpret.
I also can't comment on wether it would be sensible for you to re-familiarise with flying the type from the right seat with a guy in the left who's not confident to fly it solo - sounds unlikely though.