whats the command to set the quit message?
obviously /quit messagehere wount set it, but just disconnect you.
same with finger messages

As far as I know there is no command to set a quit message. Though you can enter a variable name into the edit box in mIRC options, then change the quit message to what you want, just using something like /set %quitmsg <new message here>, its also possable to have a quit alias, but there are many times when this will not work.

alias quit { quit messge here }

Hope that helps

Theres an option to set the default quit for if a user just /quit and no message. Alt+e - IRC - Messages

im trying to stop those from being changed

create an alias

alias quit { !quit <enter your default quit message here> }

its also work with any other mirc alias, like /remote or so