I'm going to presume that you don't want the user staying in your channel if they meet your qualifications as a drone bot.
Based on that, this should handle your requirements
Code:
 on @!*:join:#:{
  set %chan $chan
  .enable #drone.bot
  .whois $nick
}
#drone.bot off
raw 319:*:{
  if $numtok($3-,32) > 8 && !$istok(@ +,$3-,32) {
    .ban -k %chan $2 Drone Bot
  }
  halt
}
raw 318:*:{
  .disable #drone.bot
  haltdef
}
#drone.bot end