Well no it won't in case 1 ...

on 30:text:-addblist &:#:{

$2 must be present or it won't trigger

on 30:text:-addblist & &:#:{

$3 must be present or it won't trigger

Maybe try this...

on 30:TEXT:-addblist:#: {
.notice $nick usage: -addblist <host> (e.g. someone.quakenet.org)
}

on 30:TEXT:-addblist &:#: {
writeini $scriptdirblacklist.ini blackmark *!*@ $+ $2- 1
.notice $nick added *!*@ $+ $2- to blacklist.
}