You don't even need to do that. There's always going to be people who want to destroy easy targets. All that is needed to sort that is to reduce the cost to the destroyed party. Let the randoms destroy easy pickings, but don't force the victims to lose millions of credits in rebuy for the ship and contents. People playing PVE don't need to be immune to damage, they just need to have fewer repercussions when another human ruins their game. That way, the gankers get to play it "their way" and they can bravely trawl the galaxy for easy pickings, and the victims can play their way, because if they get destroyed by a human it doesn't mean having to re-do hours of gameplay.
Too many of the proposed solutions focus on the predators in these situations. What needs to happen is a shift that allows the prey to play their way.
eg: A new CMDR a week or less into the game, basically carrying tens of hours of effort tied up in their cargo, blown up by another CMDR for the lolz... Or an CMDR in an Anaconda with a cargo bay full of Palladium, blown up by a wing of FDLs for the lozl. By all means reduce the rebuy cost for the victim, but it still will not improve his experience in the game really... Because (like FD) it's ignoring the problem!
In short, how does it make any sense for the game to permit this sort of mindless destructions, ganking, bullying for the lolz?
The game should heavily penalise any illegal destruction of a Pilots Federation member. ie: If you were to illegally destroy me, your life should become hell either from security forces hassling/chasing you, financial penalties, stations refusing to let you dock, capital ships turning up in your instance! Any/all/more of these... It should be enough to put you off doing it!
More importantly, the game then needs to promote/support "legalised" PvP, something it really doesn't do at all at the moment. Tasks, missions, community goals which pit willing CMDRs against each other (if they so wish). Convoy escort/attack. Platform defense/attack. Capital ship defense/attack etc etc. In scenarios using your ship of choice, or in some cases a supplied fighter instead (think CQC). You could undertake theses missions in all modes (SOLO, GROUP, OPEN)... But in OPEN there's the chance other CMDRs will be playing along side you and against you. Voila! No more hours flying around trying to find PvP, the game organises it for you and allows you to find and participate in it easily, as part of the core game mechanics.
Introduce other mechanics... eg: Where Powerplay can in rare events trip a station into a blockade and a new mechanic is introduced. eg: A long normal flight journey to/from the station (instead of the short 5-10km one). There are then forces enforcing/breaking the blockade. As a trader, do you turn and leave, or try and run the blockade for better prices? Do you take up the missions from nearby systems to enforce or break the blockade etc? And in OPEN, there could well be lots of other CMDRs at this location...
And if the game wants to permit a certain amount of mindless destruction of CMDRs, control it via missions in OPEN. ie: Missions can be given out to destroy a Pilots Federation member in system x, y or z. The mission giver will cover up the crime. Personally I think these sorts of missions should be given out to pirates who have a high enough enough reputation at pirate stations/bases only they have access to because of their reputation etc etc...
Hell, create a community goal, where pirates of a good enough reputation have a week long "pass" to commit murder of anyone they like (even CMDRs) at a specific system. Let Bounty Hunters come in to defend the system.
....and, penalise Combat Logging!
BUT, I just don't think Frontier are interested in anything like this... Why promote and create more structured and intelligent gameplay mechanics (even if they create more interesting PvE and PvP), when we can instead simply be asked to "pretend" and "role play" this sort of stuff exists... That seems to be what's expected TBH! Look at Piracy for example, and compare what is organise and promoted by interesting mechanics in the game, and what is instead simply expected to be "role played"?
I can only speak for myself and no other PvE'rs. I would only consider open as my main platform if it was only PvE in the main. I'm not anti PvP either. Bounty hunters PvP I am fine with as each will have a fighting chance as each will be in an armed vessel and up for it. I dont mind a rascally pirate pinching cargo of me. Thats fun. But understanding that the player only wants cargo and isnt about to destroy me isnt a mechanism yet. So we just run and the pirate is then left with no options, either shoot me down or leave.
Exactly... In my comment above, you'd be far safer from threat of mindless attack by other CMDRs. Instead, you'd only participate in PvP if you basically chose too. ie: Took up the appropriate missions/tasks etc etc. How does that not make sense?
ps: You could be attacked by CMDR to pirate you, but they should be after your cargo... not your destruction for the lolz!