I have some ideas that might be worth considering
NPC followers: in all the Falouts I always wanted more NPCs. Not NPCs with histories or complex in-game relations, just generic NPCs. Raiders, BOS characters, hired guns, whatever. In F3 I liked some of them, but if one or two die then you're not left with much choice, especially given karma.
How cool would this be?
You're attacked by raiders, you waste 4 out of 5 in no time. The game quick cuts to diaologue and the last guys says something like:
"Wait, I give up! Holy #$%, I can't believe you wasted the whole gang! Look, I ain't a bad guy, but you know it's hard to stay alive out here when you're just one gun. Let me come with ya, just split some of the loot with me, okay?"
or...
"Water, I need water..."
You: "I'll give you water, but I need a mule."
"Okay, but I need water. You pay me in water and I'll be your slave."
or in a place like Megaton, instead of people running up to give you a Nuka cola or a stimpack, the run up and say "Hey, I heard you'd be back! Look, this place is boring and the caravan I came here with got watsed. I want to leave but it's crazy to travel alone. About I come with you, and you be my, uh, bodyguard? You just take any spoils off my kills as payment, deal?"
I aways wanted to see the aspects of being a slaver fleshed out more. I think slavery would take off in no time after the nukes dropped.
Anyway, these NPC don't need to be great fighters, in fact, it would be fantastic if they were expendable! They give you just enough back up to keep you alive in a tough spot, but when they get blown to bits you don't feel the need to load a game back to save their sorry hide. I hate having Butch/Charon die and then loading a game to save him because I don't have access to any other followers. Deaths a fact in the wastes, and having a few teammates go down now and then would make the world seem a little more fatal.
So how about it? Mass produced, generic, expendible NPC followers? It would deffenity add a lot to CHA or reputation stats.