First I want to give a little background on me.
I played 15+ MMORPGS and always craft and trade a lot in everyone. When I mean a lot it has been 8h+/day in some...

I played Warhammer Online and really enjoyed the PvP, it had a mening to it.

But I'm 90% crafter and trader and a 10% PvP person. Where PvP for me is kind of organised like attacking a castle in Warhammer Online, of a PvP map.

And...
I DO want open PvP in a game I play. Why?
I really like having that hair raising feeling when I'm gathering in dangerous places. Just knowing that I can in a second loose (hopefully) everything I have. Nothing can beat that good feeling.
Knowing that I'm untouchable makes me want to go and play a single player game instead.

Ok. If I ignore that it makes the game A LOT more fun for me. Why else do I want open PvP?

Easy. As a trader and crafter it sux so bad when everyone can get anything easy. No reason to trade with me, they just go out and get it them selfs. Crafters must NOT be able to get everything them self because if they do it's just a social single player game. It makes some items (raw material for crafters and in the end crafted items) rare by them selfs without the game making just drop X of a kind every day or so. I LOVE self regulated games.

If someone complain about it takes 10 person 1h to get just 1 item for a crafter, think about the value of that item! Ofc that item MUST be useful or very desirable in another way (unique looks and so on).

If a MMORPG makes me feel "Darn, no where safe and I need to go to the toilet NOW!" then I like it. I don't like when it is safe to leave a game unattended and nothing bad happens 100% of the time. Thats just plain boring.

But now the BAD BAD BAD BAD side of open PvP.
If the attacker have nothing to lose on attacking other players it will just turn to a gank feast instead of giving that thrill. First rule of a open PvP game with NO exceptions (no, never ever): Only one char per server
Otherwise people will just have a ganker char that get all the negative shit, and send all stuff to their main char.

I want a world where it takes me 15 min to get to a gathering place and takes me 30 min to get so full I must return home. Then I have the choice of gambling if I like so, to stay the whole duration and risk everything or go home early with less weight and risk less. That is I risk 60 min if I want to gamble, or 45 min if I only gather 50%. So for me that extra 15 min (33% more time) is worth 100% more material. Since I can get robbed a lot of the time and still gather more in the end. But it will sux more then I get robbed.

Runes of Magic have that BAD BAD BAD open PvP. People even gain bonus for ganking and the little negative goes away by it self with a little time (and multiple chars). So there you are ganked all the time. No fun at all.

PKing for me is attacking just for no reason except getting loot from someone (or just killing for fun). Killing (or killed by) someone my clan has a war with is PvP and fun, if I don't want to be at war I have to do something about it.

To sum it up: I never PK (I do PvP thou), but I love having PKers around to make my world dangerous as long as I don't get ganked every 5 min. PKed (attempts) a few times a day is ok for me, say once per 2-4h playeing. Then it makes my world dangerous, but don't make it unplayable.

But both PvP and PKing must be regulated so it keep the world dangerous but fun.

Personally I don't even like that the cities will be safe from attacks at the start, but I can understand the need for it.

Fallen Earth is a good game that got boring because of no open PvP. A game like FA and Xsyon need to feel dangerous, otherwise it wont feel like a post apocalypse game.

Oh, I remember. I do PK some times, if I see a bot I ALWAYS kill it! I HATE BOTS! Oh sorry, but I do hate em.

And to end it all: This is MY view, yours will ofc differ and rightfully so.