Mobs don't see invis. All the quest drops are tradeable and prelootable, our bard looted one of the orc dreadstone drops without knowing while we were still gathering the mushroom spores and once we had turned the spores in we had credit for it. Most/all of the Fear Tainted mobs are mezzable, I was careless and pulled five at once and our bard was able to keep most of them locked down, I'm not sure if we were fighting one or two at a time, but it probably saved us.
Once you gather the pieces and turn them in, everyone in the group needs to hail the alchemist and blacksmith to get the armor/potion and click it for the effect. Mercs will not get the buff making a spothealer a great thing if you use a cleric merc.
