What Browser are you using? I'm having no issues posting comments in Firefox.
Firefox. The comment box looks like it's "fake" when I go to click on it, it opens a popup which just immediately closes. Not a huge deal though, I probably should not even be commenting on anything anyway since with google+ who knows who is getting emails and stuff about it. Don't really want to be bothering all my friends with notifications because I post "lol" or "that's cool" on a video. Can go without it.
Going to be dumping my youtube account once I find an alternate site, or code a web interface myself to host videos myself. It's not like I've monetized my channel, I just have lot of random stuff on there.
Still have to decide what to do about my gmail as well, all my domain admin contacts go there, I don't know if I want to switch it to an email address that is on the domain that the admin contact is for... if there is an issue with my domain and the admin contact needs to receive mail, you can imagine how much of a pain that could be.
TBH I never had an issue with the actual content of comments, I guess it depends what kind of videos. Technical videos tend to actually have some decent comments. Though they totally botched comments a few years ago when they made a change where the order makes no sense so it's impossible to try to follow a conversation. They've only been throwing more nails at that coffin since that point.