6 - Subtitles, see http://google2srt.sourceforge.net/
10 - Safe search levels (in the status bar beside the video definition option)
11 - Show more thumbs on hover with animated crossfade
12 - Accept any URL and scrape web pages searching for YouTube videos.
16 - Restore status when a recent keyword is clicked: skipped videos, sortBar and play time
17 - Add menu entries for Most relevant, Most recent, Most viewed (Playlist => ...)