You can't votekick or voteban a player using their steam id or steam username. This makes it easy for the person to change their rp name while you are getting ready to kick them. This also allows them to change their name to that of another player's so even if you do get to type it in, it gives you an error saying there are multiple. If adding the use of steam id to votekick/ban is not something that is possible, maybe make a limit to how often you can change your rp name within a certain time span.