Yes, YouTube videos are copyrighted. When a person uploads a video to YouTube, that person "license(s) all patent, trademark, trade secret, copyright or other proprietary rights in and to such Content for publication on the Service pursuant to the Terms of Service."
In essence, Youtube becomes the copyright owner of the video. The vidoes on YouTube can still be used in some commercial situations through the doctrine of "Fair Use."
Anything that is written or recorded is automatically protected by copyright. Neither registration nor notification is not required for protection.
Because copyright protection is automatic, virtually everything you encounter online will be protected. The exceptions would be works created by the federal government, and works donated to the public domain by their creators. On YouTube, it is safe to assume that everything is protected by copyright unless explicitly stated otherwise.
Instrumental music is protected by copyright, but YouTube's automated matching system may not immediately catch an unlicensed use. See YouTube's copyright polices at the link below for more information.
More than 1million clips are on youtube
You cannot put commercial music created by someone else on YouTube as it breaks the copyright agreements. You agreed not to do this when you signed up for a YouTube account. YouTube uses special software that can identify music that is protected by copyright and will remove the audio from your video. If they have to keep doing this on your account you will be blocked from using YouTube. (See links below)
YouTube and copyright owners decide what content appears on YouTube. YouTube decides based on the community guidelines while copyright owners decide based on copyright laws.
No. You could copyright a drawing or photograph of the logo but the logo itself would have to be protected as a trademark.
YouTube has an excellent discussion of copyright on their website; see the link below.
Individual words are not protected by copyright.
Yes.
Yes. All of the photos taken in the movie are protected by copyright.
Once a work of sufficient originality is fixed in a tangible medium, it is automatically protected by copyright.