So the actual answer to the OP was that you couldn't post a comment because you were not logged into a YouTube channel but into a Google account (as evidenced by the fact that you had an email address appear up top right where someone with a YouTube channel would expect to see a YouTube username) and were trying to post with that.
In order to post at YouTube you have to be a full member of the community and use a YouTube ID to post with, just like the people who you are commenting to have.
This is done by going to your Google account's limited YouTube functionality and clicking on any button which requires you to have a YouTube ID. Or... It SHOULD (and certainly used to) but for some reason the "comment" functionality is semi-enabled for Google account only surfers and is NOT throwing up what it would if you clicked, say, "upload". Because THEN if would show you the page to create a YouTube channel (as it also used to do when you tried to comment)!
Once you are prompted to create a YouTube username and have done so you are a fully integrated YouTube user with a channel which identifies you to everyone else. It is, shall we say, the public face of your private Google account (since that is your email and you don't want everyone in the world to know it, now do you?)
You can also go to Settings / Overview / Advanced and create one that way.
The rest of your questions are addressed by JDoors. :) |