Better UX for commenting

I've seen quite a few examples of people mistakenly pressing "Add answer" instead of "Add comment" and thus getting downvotes, even though the comment itself might be helpful to the answer. In my opinion the "Add comment" button is currently misplaced. This becomes clear especially for longer threads. Since you add an answer "at the bottom", most users probably don't expect having to scroll up just to find the "Add comment" button, and thus mistakenly press the "Add answer" button. I would propose something like the following instead:

Maybe the "More" button could still be displayed above the comment section (or even somewhere in the answer header).

Edit: maybe we can also add a warning dialog if you write "@username" and if it's not a comment.