Star Wars Galaxies handled the whole PvE/PvP thing nicely many years ago -
In SWG you character could be in one of three states :
"On leave" meant you were effectively non-combatant. You couldn't attack (or be attacked by) players, or indeed NPCs of the opposite faction. Critters and faction-neutral NPCs were still free to kill you though - on leave didn't mean invulnerable!
"Combatant" status meant you could attack enemy faction NPCs but not players.
"Special Forces" was the full monty - PvP and NPC factional combat to the max.
It was the "on leave" element that impressed me the most because it allowed non-combat players (craftsmen, entertainers etc) the freedom to visit areas with high level enemy NPCs without having their faces burnt off. And by 'higher level' in this case I mean basically any combat level higher than...1

Changing your status involved talking to a specific NPC who made the switch for you, and the switch was on a timer meaning you couldn't abuse it by popping in and out like it was a revolving door.
FDev could do with taking a leaf out of that book I reckon - particularly when it comes to Powerplay and over-zealous NPC reactions to other ingame factions.
Being able to be a "Combatant" in SWG style would completely obviate the need for a dedicated PvE group entirely! Much as I love the Mobius group, a part of me is always sad that it has to exist at all - it's clear that FDev didn't think things through in development and anticipate just how many of us players don't regard PvP as the be all and end all of online gameplay.
Anyway, be that as it may, Mobius is what we have, and I'm damn glad we do!
Two Mobiuses now in fact...sort of.
Like linking two Mobius strips together into a paper chain. Hm, that'd be some scary maths in there!
