No, you can't, and this bad attitude about it is in my opinion likely why you have no clue what I am talking about.
I don't just talk to people about random shit; I talk to them about things in the context of the setting, their role, their character and the current round. Then when things happen on their own with that person, or because of it, then there's enhanced RP because it's a character I know and have some kind of investment in. It's never just inane small talk; it's mutual characterization.
As for that zombie scenario you posted; lame IMO. Same thing goes for the xeno-first contact 'roleplay.' It's all inconsequential to the outcome of the round and is more an ooc-enforced formality, especially with how TDM-like CM is currently. Even worse is that that zombies round you described sounded like a bad SyFy channel flick that I'd pass watching.
It's so bad with xenos, though, that my mind doesn't even register what people actually type. I.e. I don't process, "the bugs can use vents." I instead process, "VENT-WELDING HAS BEEN UNLOCKED."
Personally, though, I don't understand or enjoy RP'ing with hostiles here. I've never, ever once seen an attempt at any kind of conflict resolution end any other way than coming to blows. EVERY time. Because what ordinarily happens is one or both sides won't compromise or even negotiate beyond, "give me what I want now." You'll have that kind of uncertainty and tension every round.
@Build_R_
Yes I meet new characters and get to know them every other day at least. What are you doing to where you don't get to know them?