Does travelling with Danse after Blind Betrayal impact Brotherhood of Steel reputation?
I've played the game long enough to know that after the quest Blind Betrayal, you can attack any unnamed brotherhood of steel member with no ramifications. If you complete the quest and then side with any other faction that causes the Prydwen to be destroyed he will ignore you. So, you can do what you want with Danse as long as you don't go on the airship.
You can kill as many randomly spawned brotherhood members as you want without consequence, I stacked up about 80k caps selling their loot and probably hundreds of kills later they are still friendly