How can I make sure that no one can see my status on Google Talk, except people on my contact list? Right now I usually just stay invisible, because I think people can see my status if they have my email. I have no way of knowing if people have me on their contact list.
I don't think anyone except the people you accepted for chat can see your status (see the "Invite for chat" option for each contact, that's the trigger). Simply knowin your email or having exchanged emails isn't enough.