If Carriers are persistent and pan-modal then I doubt that they will be able to be damaged by players - as I doubt that Frontier would be able to find space to store the salt mountain that that would inevitably produce.
'Damaged' is relative. We can't damage megaships like the Thargoids can, but we can target their defense turrets, power couplings, etc. We can also break the hatches and steal cargo. I can't imagine that Frontier would leave this mechanic out of the game for FCs, especially considering how proud FDev was of those 'scanner effects' when they announced it. It would make for some epic PvP, but without the risk of losing the entire carrier to destruction - now THAT would bring a mountain of salt!
I wouldn't like to use NMS as a basis personally. I really do not like the game and don't think its a good model to use.
Again, I'm not talking about the details - see my post about fueling these things, and you'll see that I do
not want to harvest planet surfaces like I have to in NMS to refuel my carrier. I'm talking about the 'big picture', where my Squadron owns the ship, but NPCs 'fly' the ship. I just give orders to the crew where I want the carrier to go. I use the freighter like a mobile base, which is how I think many people are thinking FCs will be used.