#1
Hi, would it be illegal if the song is added to youtube's ad-supported list?

But also my videos will have the music videos in it as i want to upload videos of Guitar Hero Live.

For music videos do i just say that the music video is not mine and it is the bands music video?
#2
I post stuff on YouTube and I think you will be reported for copying anybody's video and posting it under your own name if it contains video or music that is not yours. I know if you copy a video outright or try to use a song that you don't have proper clearance for it, you can get deleted and banned from YouTube. I don't see it happening much but I know it does happen. I think YouTube isn't as strict about enforcing it if you don't try to "monetize" the video and look to get paid when people view it.

Someone else here will probably have a more definitive answer.
Yes I am guitarded also, nice to meet you.