There are a few tweaks I'd sure love to see.
1) The ability to turn off companion "filler" dialogue. I already know Piper is proud people want her dead. I already know Strong is bored. And if Deacon hassles me about looting ammo from dead gunners one more time I'm going to shoot him in the face.
2) Make companions get the [censored] out of your way. Stop blocking the doorway. Move to one side on the stairs.
3) If you see me sneaking how about you not run full speed ahead and set off every landmine in a hundred yard radius.
What are your traveling buddies doing to piss you off?