Can YouTube be used as a way to copyright your own material seeing as it has the date of when your video or audio was uploaded?

Answer 1

This is a variation of the "poor man's copyright" method of sending yourself a copy in the mail and leaving it unopened to prove a date of creation.

Uploading to YouTube or any other file storage service may add some additional corroboration but has no "official" status in a court of law. Under US law the only way to legally register a copyright is with the US Copyright office.

There is no requirement to register a copyright or to display a copyright notice for a work to be protected. Copyright protection is automatic, as soon as a work of sufficient originality is "fixed in a tangible medium, perceptible to human eye, machine reader or other device".