Ok so A) your kicking using # it will not work since your not on the channel...
I mean use .kick #channel because on OPEN:?: << is for privmsg the OP can be on #mirc and msg you and you will not have the ability to kick him..
EDIT: Also try it this method too from earlier.
on *:open:?:*: {
if ($regex($1-,/(myword|nextword|wow|I|can|choose|alot)/g) == 1) {
.kick #mychannel $nick Private Offensive Language
.mode #my channel +b $nick 2
}
}