I want to push my friends off of things. I think it would be really funny. I want VRchat to add an opt-in ability to shove and to be shoved. I want to push my friends into all the glamorous swimming pools and off of executive high-rise luxury suites that VRchat world makers are obsessed with.

Making it opt-in would mean it can't be used for griefing and will contain it to only people like me and my friends who will think it's funny. There is no reason not to add it. You MUST implement shoving.