I'm going to create a blog (not for any commercial purposes, it is a school project), where I am going to post the best and most classic videos of Youtube. I was thinking about buying the domain name "youtubevideos.com", but I figured that it might not be allowed to use Youtube in a domain since it is trademarked. Here I am asking. And lets say it's not allowed: will they take action? All I do is actually promoting them, since their videos are embedded and their ads show up.
No one can predict if the trademark holder will take action in a particular case. The fact is, youtube has taken action in the past and using their mark in a domain for your type of usage is trademark infringement. They could do nothing, take the domain with a WIPO action, or sue you in court and ask for damages plus treble their attorney fees. "promoting a company" does not give you usage rights, rather it makes their legal case against you.
"utube" would be considered "commercial confusion" if the site dealt with Youtube, making it just as much of an offense.
http://www.youtubevideos.biz/ The site above has been running for over 2 years now, but I would not risk it. You would be better of staying away form anything trademarked by google.