As someone who had misgivings at first, I like Blood Magic so much that it's on my "Can't Play Modded MC Without" list. Right along with Thaumcraft & Mekanism. That said I haven't gotten into alchemy a lot so I can't comment. I will say that you can keep witches with just a vanilla name tag so there's no need to gripe about jailer's safari nets. Plus witch regen is a vanilla mechanic. Then you go into factoring the myriad mod spawn methods and it's just a non-issue to me. Any OP comments seem to lean on cross mod interactions. In the realm of mods, BM is powerful but at a great cost. That's not even factoring in the learning curve. With the API release, I feel the truly genuine OP gripes will come from addons. If you feel the need to tweak then go ahead Way, it's your mod. But I'd rather you leave it alone or add configs instead of nerfing for the sake of power gamers.