Pretty much all the information you can get about power armor in the game is coming from people doing second by second freeze frames of the play trailer.
So far I haven't really seen anything in that video that would give the answers to the questions your asking so any answers you get are going to 99% speculation.
That's some pretty specific info and we've gotten next to nothing in terms of specific details on the game
Yeah that's why the best way to hunt deathclaws in FO3 was with a dart pistol, cripple them son of a guns then stay out of their reach with a shotgun. FNV I went the route of powerfist with lots of buffout behind it.
I'd recommend less panic.
Had a gunnery sergeant summed it up for me when he said, "If you loose your head in a fight, your guaranteed to loose your head in a fight."
The special attack of deathclaws was that their talons ignored whatever your DT bonus was from whatever you were wearing. So it didn't matter if you were wearing power armor or a pantsuit, they were still going to inflict full damage per swing.
The way to deal with them was to take out a leg so they couldn't charge or jump attack, then circle around them just out of their arms reach and pump shots into them outside of VATS. That was the reason for the poisen dart pistol, it cripples their limbs with 1 or 2 shots and then let you move in as the aggressor.
Just because a plasma rifle does lots of damage doesn't make it the right tool for every job.
Well I had a little advantage then because I remembered them in the other fallout games like 2, tactics, and so forth and remembered how dangerous they were at the best of times so approached my first tangle with them cautiously in FO3. Then went back and studied the fight till I spotted the weakness.
Since carpet bombing wasn't an option, then I looked at what was available and went from there.