The term of protection on a song is for the life of the creator plus 50 years (the US and some other countries have extended this to life plus 70 years). Copying without permission is a violation of the creator's rights.
You can get a license from the copyright holder, usually pretty easily.
That would be copyright infringement if the original song was protected.
Short phrases like song titles cannot be protected by copyright.
Even the titles of creative works are copyrighted and protected under copyright laws. If you use any part of a song, the title, lyrics, etc. in naming your band, you can be charged with copyright infringement.
No; song titles are not protected by copyright.
If you're using it from a commercial source it is probably copyright protected.
Anyone can create a work of sufficient creativity and have it automatically protected by copyright.
If you are taking a clip from the movie, the movie itself is protected by copyright, but depending on your use, it may be covered by 17USC107. If you are using a photograph of it, the photograph would be protected by copyright, but your use may be covered by 17USC107.
Yes. Haircuts are not copyright protected.
Using protected materials is legal if you have an exemption in the law or permission from the copyright holder.
If a song is no longer under copyright, then it becomes public domain. Typically that means that the lyrics are no longer protected. Other people can use them for whatever reasons, commercial or otherwise, without needing to seek permission, licensing, or pay royalties. That does not mean you can use someone else's cover of that song, which will be protected as a derivative work. As an example, many Christmas carols were written a few hundred years ago, and their lyrics are no longer copyrighted. So you could do your own cover of 'I Saw Three Ships', publish and sell it, etc. But what you could not do is use someone else's cover, such as the one featured in a 1999 episode of South Park, which is protected by its own copyright until at least 2069, if not longer. You could not incorporate this version into a new work until then. There are also different rules for copyright of the song and copyright of a recording made of a performance of the song. Each recorded performance may have completely different copyright owners and duration.
Websites are protected by copyright, so you would need permission from the copyright holder or an exemption in the law to use someone else's web content.
Materials are not required to have a notification on them in order to be protected.