Why do you have all of those if's?
You might as well read all of those kick messages from a text file, and instead of a prompt, why not just have it kick when you right click the nick on the channel's nicklist?
The script that you have now doesn't have any error checks to see if the nick is on the channel, and the method I just described above would easily fix that.
@ Aucun50: 'elseif's for scripts do not dramatically change script speeds at all; at least, not for every occasion.