Deleting my YouTube channel without deleting my Google account

Download a copy first with Google Takeout, just tick YouTube. Once it's deleted there's no getting the videos back, and a lot of people find out afterwards that some uploads only existed there. Also, if the channel was set up as a brand account (it has its own name, separate from yours), you can delete that brand account and the channel goes with it, your personal account isn't touched at all.

Yes, that's fully supported. In YouTube Studio go to Settings > Channel > Advanced settings and at the bottom there's Remove YouTube content. It asks you to sign in again and then gives two choices: hide the channel, or permanently delete the content. Delete takes your videos, comments, playlists and history. Gmail, Drive and the rest of the account are untouched. If there's any chance you'll want it back, pick hide. It makes everything private but you can restore it later, delete is final.