What personal information can users discover through one of my creator channels?
By default users cannot discover one or more of your creator channels just because they know another. For example someone tipping you on Reddit does not know if you have a verified Github account or not.
Users will also never know the email address or any other information you used to sign up for the Creators program.
The system is set up to provide creators with privacy in that way, however there are some ways you can diminish this privacy:
If you customise your tipping banner image and/or message to the same distinct content across two or more channels then someone who saw them both could identify that the channels belong to the same person.
You also have the ability to add links to your YouTube, Twitter, and/or Twitch channels within the banner, so linking directly to them here would allow users to find one from the other.
Also having the same username/account name across multiple creator channels, while it does not give a 100% assured link between channels, does give some potential chance for users to guess that they belong to the same person.
And obviously if you publicly promote one or more channels from one or more other channels users will definitely know they belong to you!