It’s a beta so one can assume that these features will be added in at some point. I do believe that there is an option to make the chat to ‘posse only’ to alleviate your other issue though.
But to not discourage others here, it’s not as bad as you and others make it out to be. It’s inevitable that you're going to get killed by other players that’s true, but PvP encounters do not automatically equate to griefing and from what the 10 hours I’ve played so far, it only happens when you provoke them.
But in your case, I would just pass for now and come back when they implement the features you want.