About the "ganking" issue: we should consider that in PP2 you'd have teams, and that would be very visible in the radar.
In an Open Only environment a group of PvPers would go where you see more action in the game menu, and for the players trying to give their contributions there will be PLENTY of systems to fortify up to the Stronghold state: Powerplay is designed to be VAST, and if you are able to see where there's more action you can see where there's less action too of course. It would fit the different gamestyles even in an Open Only environment.
I think that if a group of PvPers will try to do a blockade in a particular system they will attract at some point other groups of PvPers, making it easier for all the players to do their part. Of course there will be players capable of do more and players capable to do less, but that's what competition is: you can't always win, sometimes you need a strategic retreat or simply to accept the loss. And that's fun too, if you think about it.