You can often identify to a nick while not using it with /nickserv identify <nick> <passwd>
If that's the case on your network, you can replace that script with these two lines
Code:
alias ident .play -ap +ident nickserv nicklist.txt
alias -l +ident nickserv identify $$2 password


If your network doesn't allow identying to a different nick than what you're currently using, this has a 2 second delay between each nickchange/identify. You can adjust the delay by changing the "2000" to whatever you like (in milliseconds).
Code:
alias ident .play -ap +ident nickserv nicklist.txt 2000
alias -l +ident {
  tnick $$2
  nickserv identify password
  nick $mnick
}