Works of sufficient originality are automatically protected by copyright as soon as they are fixed in a tangible medium. If formal registration is available in your country, you may choose to do that as well, although it is not required for protection.
Not legally, unless you own the copyright or have obtained a license from the copyright owner.
figure it out your self
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".
If you are using materials that are not your original work, you need permission from the copyright holder. Works that are entirely your own are automatically protected by copyright as soon as they are fixed in a tangible medium.
Copyright
You are legally allowed to make copies for your own use of any copyrighted material you own, so long as you do not distribute the material. In some cases, donating originals after making copies for yourself may be considered as distribution.
You couldn't, because it isn't your own original creative work. You could copyright a photo of your face, though.
Legally...no. But, for insurance purposes, yes.
That would be a copyright
Yes, it does. Just like any other Copyright.
A company doesn't have a single copyright date; each copyrightable work it produces would have its own date.
You may only use images that are your own original work, in the public domain, or for which you have a license from the copyright holder.