OK so it really bugs me that i don’t think you can sell things without NPCs so i was thinking about turning them on…or if someone knows a mod that just adds people the buy and sell things that would also be nice 
Define ‘safe’. Static NPCs will get refugee centers and later the ranch populated with a couple people capable of selling or buying things. Their inventories restock every couple days now as well.
By safe i mean it’s not super buggy. or even very buggy.
Static NPCs are perfectly fine in that department in my experience. Random NPCs used to cause crashes for me but that’s been rectified (their heads explode to avoid shit like infinitely trying to eat a lighter and thus cause a crash) other then that they’re in a pretty non-buggy state. Though bandits don’t seem to be automatically hostile/register as such recently. So you can’t preemptively attack without suffering a ‘killed an innocent’ morale penalty.
They are pretty buggy at the moment but they won’t break your save or anything like that.
Ok cool Static NPCs it is then
I got mugged and I killed the woman who mugged me afterwards.
I got the innocent kill penalty.
Much bug.