Yes, unless you control the copyright and have chosen to share the materials in that manner. Distribution is one of the exclusive rights of the copyright holder.
Yes it is a violation. Youtube is attempting to crack down on this but due to there being hundreds of videos being uploaded a day its very hard to do so. Some videos are getting taken down if a company finds it a violation to copyrights, like if someone did a Family Guy video, the Fox Network could report and have it taken down.
Usually they simply take down the copyrighted material. They could bar you from the site but it rarely happens.
Either find another audio file, one that isn't copyrighted or is free-use, or contact the owner of the copyright and ask them for permission and the conditions under which you can use the material.
Submit only videos to YouTube that do not contain material copyrighted by someone else or get the necessary permission before you post.
Yes, unless you have their permission to record a live musical performance, it would be a copyright infringement. Similarly, if they do not have permission to perform and record their rendition of a copyrighted composition, your recording of their performance would be a copyright violation and uploading it anywhere would be a further violation (unauthorized publication of an unauthorized recording).
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.
I think that the only videos on youtube that are copyrighted are like the Vevo videos, or like the Videos uploaded by the band themselves.
If a song is on iTunes, chances are that there is somebody who holds the copyright rights to the song. If a song is copyrighted by someone somewhere other than YouTube, then the copyright will still apply when the content becomes available and able to be viewed on YouTube.
Some video distribution sites use automated matching systems (such as YouTube's ContentID) to discover and block infringing material; other sites rely on humans to discover and block infringements, and are therefore much, much slower to notice.
According to the rules for Youtube you are not supposed to post copyright material on the site. So theorietically there should be no problem with downloading from youtube; however sometimes people do illegally post copyright material. Therefore you need to be careful in downloading from Youtube.
According to the terms and conditions, the user is responsible for what they upload.
Copyrighted content is difficult to find on YouTube. Copyright owners are able to file a DMCA takedown notice to content that infringes their copyright on YouTube. Thus, it is unlikely that you'll find any full episodes of YuGiOh on the website.