PVP? Really? I never play on a server and I adore witchery for what it does. Sure you can use poppets against other players (and curses), but you can use quite a bit of things from mods against other players (various traps in other mods, landmines etc etc) . *shrugs* honestly you have such a biased against witchery I doubt I can persuade you.
If the idea of tinkering with potions, circle magic *and no all of it doesnt need covenant witches, sure some does but not all), etc doesnt appeal then dont use it. I was merely making a suggestion of a mod that is heavy nature themed and contrary to popular belief isn't pvp centric. Or I would have grown bored with it long ago as I always play single player. But the potions, the fun circles (bartering with demons is always a hoot) itself is more then enough for me to adore every second, heck people make entire lets plays of single player witchery only that should say enough that there is way more then pvp.
I just now spent some time making treecutting/leafremoval potions to help me cut down a small forest, kinda nice since I dont have the terra axe thingy from botania yet, so cutting them down by hand would not have been fun. always keep a brew of webs handy as soon as i can make it in case i need to leg it from mobs before i reach the "yawn mobs, yeah yeah beat yourself tired on my armour" stage. etc. So much you can do with the brews alone.
But perhaps I am strange in loving witchery on a single player world, I am strange in many other ways as well after all ^^