i would go with mirc's /ignore set up as napalm` said
EDIT took out the join event cuz you want to see joins
heres ur version with ignore setup & echo's

menu nicklist {
  . $iif($ignore($address($$1,2)),$style(2)) Add $$1 To Ignore List:{ .ignore $address($$1,2) | echo -a $$1 Has Been Ignored }
  . $iif(!$ignore($address($$1,2)),$style(2)) Remove $$1 From The Ignore List:{ .ignore -r $address($$1,2) | echo -a $$1 Has Been Removed From List } 
} 
on ^*:QUIT: { if ($ignore($address($nick,2)) == $address($nick,2)) { halt } }
on ^*:PART:#: { if ($ignore($address($nick,2)) == $address($nick,2)) { halt } }

heres it again with ignore setup & $input box's

menu nicklist {
  . $iif($ignore($address($$1,2)),$style(2)) Add $$1 To Ignore List:{ if ($input(Are You Sure You Want To Ignore $$1,uqy,Ignore $$1 ?)) { .ignore $address($$1,2) | noop $input($$1 Has Been Ignored,uio,Ignored $$1 ?) } }
  . $iif(!$ignore($address($$1,2)),$style(2)) Remove $$1 From The Ignore List:{ if ($input(Are You Sure You Want To Remove $$1 From The Ignore List,uqy,Remove $$1 ?)) { .ignore -r $address($$1,2) | noop $input($$1 Has Been Removed From List,uio,Removed $$1 ?) } } 
} 
on ^*:QUIT: { if ($ignore($address($nick,2)) == $address($nick,2)) { halt } }
on ^*:PART:#: { if ($ignore($address($nick,2)) == $address($nick,2)) { halt } }

/help /ignore and /help $ignore