Some great suggestions here!
While you have written quite a lot of different ideas for me to individually give feedback for each one, I'd like to at least clear up some misconceptions below:
Certain things I'd probably add a twist to, just to completely ensure it doesn't bring about issues in the wilderness. If the intent is to give a new set of autokeep gear for PvM, the strongest aspect of the set (range strength from armor pieces) should be discarded or reduced for PvP combat only.
I believe the issue is the actual magic levels of certain bosses. If they're intended to have a high magic level, or even have a spell based combat system, they still might not have the proper level in their back-end. I'll start to look into this and see how many bosses actually fall into this category.
A rate buff for this boss effect was tried a few updates ago, but apparently it has not made much of a difference? I'll take note and look further into it, thank you.