Only just read this thread after being in hospital February, March and April. Still catching up. By PPM do you mean Parry People Mover? Sorry if I appear pedantic but I like to be sure with abbreviations.
If it is that, will there not be problem with capacity and one isn't passed for use on a main line because Stourbridge Junction to Town is a closed dedicated route with no other traffic unlike Cowley having to run on the mainline into Oxford.
With that number of stops, would it be better and quicker than a bus? And all those stations or platforms; who would pay for them even if one or two coaches long? I'm all for rail reinstatement, but this is just too many. If Oxford had trams then this would be a different matter and Cowley could be a tram extension and have all those stops without the need for platforms.
I think that's just that poster's fantasy.
The more grounded proposals are a reopening with two additional stops and resourced by Chiltern extending some of their Marylebone services that currently terminate in the bays at Oxford.
Potentially GWR could get in on the act by extending Oxford-Banbury shuttles? Or possible some Turbos that current terminate in Oxford from the Cotswolds?