Yeah, rooting would solve the main issue of not being able to remove Google Talk at all from many stock Android phones. But, for folks like me who doesn't want to root our phone (for various reasons), my suggestion above works fine.
Answer: To truly disable Google Talk you need to open up the "Talk" app and then Sign Out of all Google e-mail accounts that you may have. Trying to "Disable" the app in Settings doesn't work as you'll still get chat requests for some reason.
This was tested in Android 4.1.1 (Jelly Bean) on...