I tried to delete my YouTube account today as a test. I failed because it seems the only way now is to delete all your accounts on Google, including Gmail and Google Docs. Google basically wants to take over my identity and manage it. "You can check out but you can never leave at Hotel Google" is what I fear. What if I did delete everything? Would that even work? Don't know.
Google is moving to one account for all of Google, like it should have been in the first place. Of course deleting your YouTube account would delete everything else.
It's certainly not a great solution, but I practice 'clean room' browsing, by using one browser where I log in to services like GMail, and one browser for anonymous stuff.
What happened to "Don't be evil?" I turned that off but the problem is you're never sure if you've actually handled something correctly because they make it so darn difficult.