There certainly was a "too many characters" problem in the movie and its obvious stuff got cut in the reshoots, but the originals were not exactly character exploration vehicles, either. Luke was basically the only character that had any sort of time spent on his backstory in either of the first two. But compared to the prequels which were jammed with "please give me a cameo so you can make a toy with my name on it" people and outright horrible main characters? Can anyone even remember anything about the Jedi in the prequels, beyond Mace who was Jules with a Lightsaber the whole fucking time?
Despite the gaps, this movie told you everything you needed to know about the characters with a few actions or statements (again, a lot like the Viet Nam war movies it seems to heavily draw from) for the purposes of the story. I don't need a GRRM exposition on some dude who is going to die or otherwise never be seen again in the movies. When Cassian did what he did in his first scene, it gave you everything important about his role in the story. The female lead's personality turns are where it fell flat, and I think that's probably also due to the reshoots. I am guessing that there is a bunch of shit with Saw that we did not get to see in the final cut, probably because it was already the most dragging part of the film due to it being the gather the characters bit. I guess we will know when the home release hits.
As for the Vader "pun", he has always been a passive aggressive threat guy. I mean, did everyone just forget these quips?
So yeah, Vader snark has been a thing and was present in all of the original trilogy movies.