That gear is barely relevant in Valigarmanda normal because it level syncs the gear. By extension this item level syncs it also. Provided you are even in level 95-97 leveling gear, you already outgear the fight and will sync down.
Rarely. I had a healer die in expert a few times the other day. Duo'd a boss and continued to kill a big pull with the DPS as if the healer didn't matter, because they didn't.We still die I promise you.
I do think it is ridiculous. I don't think there should be a specific type of attack that happens only when everyone else dies. But I think some very basic things should happen that used to happen in Heavensward:
heavy auto attacks such that it cannot be handled by the tank alone and requires a healer, Ahk Morn stack markers that with enough frequency are beyond what the tank can realistically invuln and mit through, adds that themselves deal so many autos that if there isn't and OT and healers it's over.