About embedded videos
First of all I have to say thank you for this great userscript!
Anyway, if you take requests, I'd have a small suggestion for handling embedded videos. I never watch embedded videos and it annoys me to have to enable flash (I've disabled it by default for security), click on the top left link and watch the video on youtube in real size. It takes time, and on slower computers it lags too and gets very irritating. I would like an option in YousableTubeFix to turn embedded videos into just links with the preview image. Like, just replace it with http://i2.ytimg.com/vi/[VIDEO_ID]/sddefault.jpg or maybe default to the hd version and use sd as fallback (by checking the width/height). Links would also be easier to just right click > copy link if needed.
I could probably handle that myself, but since you already seem to know quite a lot about how youtube works, I'd rather not make a separate userscript of it.
The new layout only uses 460 pixels of a 1920 wide screen and only about 300px of that is non-whitespace. Also the video items are so tall that you can only fit a few of them on the page. On top of all that, it defaults to "View > Highlights" which often hides not-so-popular videos from my friends, and even if I change it to "Everything" it keeps changing back to "Highlights" when I least expect it. I have no need for anything in the left side pane and I don't care about recommendations when I'm looking through my subscriptions, though they are sometimes nice for finding something new.
This part isn't really a feature request but if I never get around implementing it, it could be a nice addition to YousableTubeFix too. Or if you have any suggestions on how to keep up with my subscriptions in a more usable way than the front page, please tell :P
EDIT: Ah, I see there are quite a few userscripts that already do this. Maybe I'll try them if they're not conflicting with this one.