Theres really no limit to that. Well, if the interactions are between player characters. If its between you and another player controlled character, than have at it.
post away

But If it has anythingto do with the NPCS and plot driven development, then you'd have to wait for a Jabber update.
Of course because obviously you won't be allowed to just simply post 'blablabla gets away without the marines or whatever with them doing nothing to me'.
Not happpening.