As I recall, a Deathclaw shouldn't be able to wear armor at all. So that sounds like a bug. However, I noticed that a Tesla armor I found in this mod (maybe Quartz?) when equipped looked like the character sprite wasn't wearing any armor, so there's something fishy about that armor in the first place.
I also noticed that the long-standing Felicia bomb bug in Quartz is still there (bomb explodes pretty much instantly for no reason, but you still get the quest to save her completed) and for some reason when I spoke to the Mayor about saving his wife, General Barnaky appeared in the Mayor's office. That's never happened to me before, so I suspect someone's been mucking in the code on these self-install versions Pyran's been posting.
I can equip deathclaws any armor, their sprite change except with that specific tesla armor, found couple of armor specific for ghouls and super mutants but in general armors/armor rating in a total mess in this mod.
Right now I'm playing on insane and it's a little bit more challenging, but still not deep into the missions.
As for Quartz and saving the girl from the bomb, I peaked from behind the door, shot with a minigun one of the guys and the bullet accidentally hit her so she started running toward the door, so the explosion didn't kill her.