You're banning kids from a game because they can't figure out how to use your crude command line utility on the first try without making any mistakes. Why not just add some basic filtering and error checking? A computer program should not be doling out bans based on something as subtle as a username. Consider the following two examples:
John Smith joined the game
/setname John Smith
<banned>
This user is a normal person and is shocked at encountering such a hostile environment. He will likely not return even from a temporary ban.
xX--Qw1kSk0p3--Xx joined the game
/setname carrot B cigarettegins
carrot B cigarettegins: perpar ur star fish
This user is experienced with hostile environments because he creates them everywhere he goes. He will wait out the temporary ban so that he can return and inflict suffering on others. In fact this user will be highly attracted to this game mode because of the obscure rules that result in severe user punishment.
you know as well as I do that I cannot feasibly determine the difference between "John Smith" and "Placebo Doctor".
In that situation, placebo doctor is not a valid roleplay name, and the user should not be on the server.
I apologize to John Smith, but if you try to set your name to something that is (at least most of the time) invalid (your username) you're getting banned.
In addition, if you are unable to understand the admittedly slightly vague instructions, you also likely cannot understand other instructions, and you too should be removed from the server.
How about this: I modify the mod to have an auto ban severity option.
Level 0 - fully disabled
Level 1 - reports user to online administrators, unless none are online, then it does... What?
Level 2 - auto ban functionality as it currently is.
At the very least, I'll make it disableable.