For the typing issue, they could have something like a quick message system, like on most phones(If somebody would text you "Well, have a good night", a quick messages would appear over the keyboard/typing area that would say "You, too!).
How would impostors justify themselves for their actions
Voice Chat would likely be the most plausible outcome. It will only be enabled during meetings or pre-game.
Voice Chat isn’t available for the main game yet, so I wouldn’t expect it to come to console soon.
I had just meant, when and if a console release happens, that will likely be the best way to go about it
