If dungeon mobs were immune to instant death, then there would basically be no reason to not have blue have an optional "for duty finder" mode as they are the most OP thing that blue can do in dungeons that would significantly reduce clear times. As for the other changes, mighty guard should probably retain some penalty, otherwise there would be no reason not have all blues in mighty guard, it just needs to be a much less harsh than currently is, otherwise I agree with a lot of this.