Firefox extension to enhance keyboard shortcuts on YouTube.
I use the firefox extension and AHK script myself. If you find them useful, that's great. They're not too polished, but work for me.
There's an AutoHotkey script which is not required by the extension. It's so if you bind spare mouse buttons to F15 and/or F16, you can hold one of those down and scroll the scrollwheel to change playback speed (while using youtube). F15 scrolls with < and > (which are the standard youtube shortcuts), and F16 makes the scrollwheel change the speed with , and . (which requires the youtube-speed-tweak firefox extension). There are some other F15/F16 related key combos you might want to remove from the script before using.
Install and read more about the firefox extension here:
https://addons.mozilla.org/en-US/firefox/addon/youtube-speed-tweak/