Possibly, every viewers delay is different though, so your Extension could cache/delay pubsub processing of a message in a queue, until the right moment time.
No, but something could be written, extension side, but extensions don’t run/play on vod’s right now for that sort of thing.
Perhaps but that will be different for every user, and it’s only available in a video extension now a panel extension
Does this require the user to download something? Or is the keyboard listening to Chrome/WebBrowser? As users are not supposed to download something for the extension.