I actually strongly dislike pvp in survival type games, as the point of most of them is to survive vs the environment, once you throw pvp in there, it just becomes a gankfest. Don't try to say it doesn't it ALWAYS ends up this way no matter what kind of rules they try to do. Will to Live Online has a thing where if you pk someone in cold blood anyone can hunt you for a while with no penalty, and this still doesn't deter greifing and such at all, they just do it all the more, and now aim for new players even more that have no chance in hell to actually kill them.
The best way to put pvp in these games, is to have a seperate zone for it, that once you walk into it, its open pvp. I used to play a mmorpg that did this, most of the game is pve, however, there is a open pvp zone where rare resources only spawn there, and you have to build and protect extractors from other factions to get the rare mats. The fuel to run said extractors are also made by players, as almost all items in the game are player made. So even someone who doesn't wanna pvp can get in on it by providing fuel to sell to the pvpers. Full open pvp never works in a game these days as most pvpers have no respect for any other player in todays gaming world. It was different years ago. I used to play alot of open pvp games back then and they never had the greifing problems the games do today.
For me I don't mind open pvp if there is no item loss for me if I get ganked, and if my base can't be nuked.. well the base thing depends, if its fast to rebuild its not so bad, like say fortnights pve side, its easy to rebuild. But in 7 days to die? hell no it takes way to much time to build and gather stuff only for a player to destroy it in minutes. Players only need a 1 wide 2 high entry to get into your base. I';ve never been a fan of pvp systems that force loss of progression when you get killed by another player, by item loss or other such things, as it just fuels greifers to do it more. Even more so if the items you drop can be looted by said greifer.