now does the owner of these videos have ability to remove their video as they please, even though I have the video on my site?

And also I'm big on reviews and previews of certain things like video clips, songs, albums, movies, etc... and by doing this, does it hurt me in anyway, like my chances of getting affiliates ads and such, if I'm discussing about there product in not a good light?

Also is the embed code the only way to know if its OK?

Can I get a commission of some sort for directing them (the viewer) to there homepage where the video is based, if they choose to double click the video, as you say directs them to the source, when it comes to YouTube videos?

Thank you, for your time and help!