The Affiliation page states that an Active Membership application may be submitted via e-mail. However, it also says that a photograph and a signature are required. If I were to e-mail my application, would I still need to snail mail a confirmation letter and a photograph, or could I also submit a photo electronically and skip the signature or verify my identity some other way?

The photo may be submitted electronically in .jpg format, it must still meet the other requirements, i.e. be a typical profile photograph of yourself where you are the subject and clearly identifiable, and not electronically altered to misrepresent yourself.

The signature can simply be your name typed at the end of your application, certifying that it is you submitting this application.