If you want an unexploitable way of integrating pvp into powerplay, an
elo system is probably the best way to achieve it. There's a good reason why so many other games use one.
The basic premise is simple; each week, everyone who participates in pvp is given a ranking. If you win more than you lose, your ranking will be higher; if you lose more than you win, your ranking will be lower. And if someone with a high ranking kills someone with a low ranking, they don't rise much, while if a low rank kills a high rank, they get a lot. Points are never created or destroyed, only traded. At the end of the week, you reward players based on their ranking. Someone in the top 10% of players gets a lot of points for their team; someone in the bottom 10% gets a small amount of points for their team.
This system cannot be effectively gamed; for example, say you make five alts for the purpose of grinding elo. You have them join the enemy faction and you kill the first one until you stop getting points anymore. Then you kill the second one - only, you're much higher rank than him now. You can only kill that one a few times before you stop getting significant rank. Then you kill the third one, only now you're not getting ANY rank.
Now you're in the top 25%, but you've added three enemy accounts that are in the bottom 50%, virtually equalizing it out. And now, you're well above your intended ELO, so if you get into a fight, you'll tend to lose more elo than you gain.
Yes, there may still be convoluted ways of manipulating elo, but they start to become complicated enough to be easily recognizable, and they can easily be solved by banning the players in question from Open.
It would also be neat if CQC were made a part of powerplay, somehow. Powerplay is more than just warring over systems, after all; it's a competition of
influence, and winning a big, highly-visible event gains influence as well. There's a reason the various countries join the Olympics.
And the best part is, CQC is, for the most part, fair, so you don't need to worry about equipment or anything other than skill. And if people could get powerplay merits just for doing CQC, I think they definitely would give it a shot, potentially dragging it back from the abyss!