is the dog optional?
I think you find him as part of the main story, but you don't have to have him with you.
You can swap him out for 1 of the other 12 companions in the game (including your Mr. Handy).
Or, you can tell him to leave you alone, and he'll return to wherever his/your home is.
Speaking of save scumming, What are your guy's thoughts on dog meat being immortal and the fact that some NPCs being unkillable because they are essential to the story?
For Companions, I don't really mind.
I mean, in FO3/NV and in Skyrim, I could never actually tell if companions were supposed to be immortal or not. For a large part of the game they'd get knocked down in combat, but not die. And then usually at some point they'd become mortal, and it would come as a surprise when a super-mutant or a dragon takes their head off.
I've no idea if that was level-based or not.
I also understand their point, that for most players, they just reload if their companions die. And I'll admit, I've done it, especially when I'm using them like an extra bag and they're carrying all my good loot, and they suddenly decide that they're now capable of dying.
Maybe it should have the option of being turned off however. If there's a New Vegas style Hardcore mode, then that should let Companions permanently die, as that was possible in NV.
But most people play more casually, and it's just easier for them if their companions aren't being evaporated by bandits.
As for NPCs, I'm not really sure what it will include.
There always were non-killable NPCs in FO3/NV. I don't believe your dad can be killed, for example.
I don't think they'll have any enemies who can't die, and simply escape, because that sort of battle hasn't been in any of the Fallout games at all.