1. if the server allows, use enter key on the number pad to swap 1st and 3rd person view.(i rekeyed my logitech thumb mouse button to that enter fer easier use) the f key allows to swap between fire modes fer your weapon and any grenades, chemlights, tin cans and flares. the normal enter key can be used to open the action window. ie. if nothing else is under cursor, it will show just your weapon and if you click enter or lmb it will select that item. this is how you pick up items, bloodbag friends, or open doors.