You can use your notify list as an impromptu "buddy list" with the following one line script. No need for anything from hawkee or mirc.net. Add the following to your Remotes (Alt+R -> Remotes):
on ^*:OPEN:?:*:if ((!$notify($nick).ison) || ($istok($notify($nick).note,ignore,32))) halt
Then add your friends to your notify list. You probably have some there already. You can find the notify list editor in Alt+B -> Notify or type /notify NICKNAME or /notify NICKNAME NETWORK (for network specific nicks), and you can your online "buddies" at anytime with the notify list by pressing Alt+N or going to View -> Notify List or even by typing /notify -l. That makes a perfect buddy list.
You might have people on your notify you don't want to to message you. To ignore someone you simply add the word "ignore" to the "Note" field in the notify list editor for the username. If you use the note field for other purposes and don't want this behaviour, simply remove
from the if statement above.
Using the notify list also gives you the extra bonus feature of getting notices when your "buddy" gets online. You can also see them in your list when they're online, which is helpful.
Finally, if YOU open a query window with any user, they will not be blocked from messaging you until you close the window, so you don't need to worry about initiating conversations with non-buddies.