There are forums for that such as https://productforums.google.com/forum/#!forum/youtube
And about cancel. My advice is to not do that. Just let it sit unused.
Bob
I have a second YouTube channel on one of my Google/Gmail accounts and I had an additional Google/Gmail account that i created a new channel on.
So in all I am working with three channels, a default YouTube channel I created for both gmail accounts and a second channel on one of the two YouTube channels.
I made the second channel on one of the accounts and I want to cancel one of the two gmail accounts but I don't want to lose my second on one of my accounts but it is co-managed by both Google/YouTube accounts.
If I delete the Google account that the second channel is created on but it is co-managed will I lose this channel? If it is co-managed could it still be up and running even if the account it was created on is deleted. I no longer need a second Google account so i want to just delete it.
But I don't want to lose my YouTube channel.
Can I still keep my secondary YouTube channel as it is not the default on either Google accounts or will I lose it?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic