What are all the Google Reader keyboard shortcuts?

I'm also busy learning how to be maximally efficient in Google Reader so this is a valuable exercise for me too. There's quite a set of different keyboard shortcuts available in the program, and I dug up the full list by checking Google's fairly extensive Common Questions document.

Here's the full list:

Of these, I have to admit that most don't seem too useful, and some are confusing in their overlap. For example, while there's an apparent difference between "j" and "n", since I always read my feeds in "Expanded" view, they exhibit exactly the same behavior when reading a set of feeds.

I'm most intrigued about sharing items, however, and that's next on my list, to have a URL where people can look over my shoulder and see what items in my feeds I think are most interesting. That's the "shift-s" (or "S") shortcut, btw. I still miss the ability to annotate my shared items a la Bloglines, but perhaps as I dig into the sharing capability I'll find a similar capability.

Anyway, those are the most critical shortcuts. For the way I use Google Reader to keep up on RSS, I'll candidly admit that most of 'em are irrelevant (for example, I don't change views or open or close individual items) and I still read, oh, about 170 feeds on a daily basis. Am I missing key features and capabilities? Perhaps someone who has had more time using Google Reader can comment on this?