Hello friends. I assume you already discovered the not-so-new keyboard shortcuts in the #Youtube web interface, e.g. option+left/right arrows to switch between chatpters in the video, if they are present, left/right arrows to move through the video, less-than and greater-than sign keys to speed up and slow down the video, digits move you quickly through the video. 0 is beginning, 1 is 10%, 2 = 20% etc. Of course, substitute option for alt on Windows.
Hope this helps someone?