In Yahoo Messenger, when I'm signed on as invisible, and I right-click a contact and in the Stealth Settings I set "Appear online to ", can I set a status for that contact to see? And the rest see me as invisible?
Exactly, that is the purpose of stealth mode. You can appear online to certain contacts that you want and be invisible to the rest of the world. Just right click on any contact and in Stealth Settings, choose Appear Online.