Can weak auras create a way to show when a preset list of people are online and show

[scorpinot]

I was thinking It'd be cool to connect all the master crafters on a server in one single chat channel.

If this can be done, I imagine the follow questions needs answered to determine so:

1.) Can you have custom variables sent between players that triggers when a player with a weak aura logs in and hits the log out button/exit game/alt+f4, or toggles when a player hits a custom macro button?

2.) This (https://www.reddit.com/r/woweconomy/..._friends_list/) WA might be of use but requires they be on your friends list?

I also wanted to ask if WA could make a dropdown menu list showing all online crafters or on a button press?