Must have.
Walking mode: press (___) to stop running and go slower. Good for non-fighting maps like bases and RP.
Sit animation: proper sitting, not crouching like in PB2. Good for RP maps too. Sit on a chair, or edge of the roof.
Interact animation: move your arms to actually do something like pressing buttons (panels with USE word on the screen) or grabbing guns, instead of using telekinesis like in PB2 where you activate panels with the power of your mind.
Better crouching: ever wondered why when you crouch behind the wall to cover from bullets your head is outside and gets shot at? It's because the height of the crouching player is fixed, not flexible. Make it flexiable so player can control how low will he crouch.
If you like the ideas, send the topic link to Eric so he can notice it.