Well I can definitely see the benefit of people talking English-only, mainly because we know 47 speaks a crap ton of different languages. But I would certainly appreciate them talking in other languages, and if that is not the case then at the VERY least talking in (non-offensive, which means non-exaggerated, subtle) accents.
As for the "comedic" lines. Yeah, I hope we have more serious lines in-between in the final build. I don't mind the "funny" lines like most of you, but how goes the phrase? "The dose makes the poison". So basically, keep it in balance with the serious dialogue, so the game doesn't feel like a joke overall. A little bit humor here and there, but not TOO much.