This is interesting but I question its accuracy. I'm not entirely sure how potency works but If you are correct and buffs / debuffs etc don't actually affect potency itself then PPS isn't necessarily a good indication of a players performance. a player could achieve quite a high PPS but actualy have a negative impact on there actual DPS.
A warrior for example could never touch the storms eye combo at all or let it drop off for long periods of time and just do more paths or bb combos and from a PPS perspective this would be seen as good play because the 20% damage buff from eye wouldn't affect actual potency. all those extra bbs might actual increase the pps
another example would be monk. in terms of potency a monk would basically never touch dragon kick or twin snakes. boot shine and true strike both offer larger potencies in there respective forms.
or ninja. skip suiton and use ration all the time. tcj your dotons. (if I recall the tcj buff actually means the doton combo is more total potency than the suiton one.
this could then lead to quite a lot of false positives as an increased PPS number could actualy result in decreased DPS.
So I wonder how usefull a PPS number would actually be. as you could effective suck at keeping self buffs and things up but still achieve a high PPS in which case it wouldn't really tell you anything about how optimally you are playing..
it is an interesting idea though.