Chances are they'll keep on coming back after being kicked.

I believe regex will work best for detecting a URL with one line, but if you don't know regex, you can do it with $wildtok and a loop like this:

on @*:text:*:#:{ 
  var %b 1, %c *www.* *http://* *.com* *.net* *.tk* *.us* *.co* *.gov* *.org*
  while $gettok(%c,%b,32) { 
    if $wildtok($1-,$v1,0,32) {
      ban -ku30 # $nick 2 You've been kicked for posting a link.
    }
    inc %b
  }
}

This will ban them for 30 seconds and kick the offender.

Your approach of using one text event per routine is rather repetitive, and the remote size will get a lot bigger than you think when you decide to add more over time.