I don't think Oculus Rift is a good purchase if you want to play online games, you will be disavantaged a lot ( dunno if u can say that in english but what I mean is that you can't be better at aiming with the oculus rift than with a mouse) Oculus Rift could be good for games like Amnesia, The Forest, slenderman etc... but not Rust first cuz the survival aspect is inexistant ATM, and 2nd because you will struggle at killing people wich is what the game is about FOR THE MOMENT
Apparently you haven't had the privilege to play with one yet. You can still use the mouse and keyboard. And the aiming factor is done through the mouse still the only reason for the headset is the "camera view" and which direction your looking. but you can still aim with most games with the mouse.
it adds that 3rd dimension of gaming.. The "mouse look" is off but the aiming on the screen is still on and the gun moves around the screen as if your moving it around in RL while looking 1 direction.