Nothing too over the top? it's people clearly getting killed on screen, what do you want them to show in a PG-13 movie, flying body parts?
The only thing The Winter Soldier questions is who Captain America is? he wasn't questioning what he was doing up until the climax, before that he's killing and down for the cause even after asking about Captain merica which is why he accepts the wipe after the talk. None of the character's killing had to be in the movie at all. Like I said before it could have just been him only encountering and fighting Captain America and no one else with zero causalities. Along with just saying that he's an assassin. That would be protecting and neutering the character. Instead they didn't and showed him flat out killing and assassinating people. So why do you think they won't do the same with Thanos?