Here’s the story as I know it: When people started making movies, they settled on a more or less “standard” aspect ratio. This ratio was originally 1.37:1 and then changed to 1.66:1. This is slightly wider than a standard tekevion set which is 4:3 or 1.33:1. Until the 1950’s movies were shot and projected in this aspect ratio. (Aside from some random stuff in the 20’s. Everything happened in the 20’s, but most of it didn’t catch on… Death rays) At the same time that Hollywood was pioneering the moviemaking business, televisions were slowly making their way into American homes. The earliest television sets had basically round screens. I believe this was for technical reasons to do with the CRT technology. As time went on, the people who made televisions got better and better at controlling what they were doing. So much so that by the late 40’s (I think. The dates are approximate.) they could sell a television with a rectangular screen. The aspect ratio of that screen was 4:3.
“Oh noes!” said Hollywood. “People will watch television instead of movies because they’re the same shape!” And thus began the 1950’s, in which projection methods were changed to make way for wider and wider screens. Ben-Hur, for example, was originally projected at 2.8:1. Now most movies are shot and projected through anamorphic lenses (essentially a fish-eye lens so you can put a widescreen image onto standard 35mm film). The aspect ratio of this method can be essentially anything, but the standard size is 1.85:1. The 16:9 ratio (1.78:1) that your television has is actually a compromise between the 4:3 television ration and the 1.85:1 movie ratio.
As for your questions, pan-and-scan does refer to a technique of editing movies which were shot in widescreen (typically 1.85:1) to show them in “full screen” mode. That is, so your TV is always full. There are a lot of problems involved with filling a TV screen with image. Here’s a (somewhat) technical discussion of the problems and where they come from: link.
Widescreen means that the movie is formatted to show the full theatrical image. This probably involves narrow black bars even on your 16:9 screen. Full screen means that they’ve recut the movie to display on a 4:3 television set. As in the above link, there are a lot of problems.
The other information used to describe the aspect ratio (anamorphic is the most common one I see) are, for the most part, completely irrelevant. I don’t know of any reason why you would need to know that a movie was shot using anamorphic lenses or by masking off the camera. The masking process is called matte-ing.
If you want to watch old movies on the 16:9 unit, you’re just going to have to learn to love the black bars on either side, just like I love the black bars on the top and bottom of my el cheapo TV set. 
If you’re looking at some DVD in Wal-Mart, the magic words are “presented in a format preserving the aspect ratio of its original theatrical exhibition” or something to that effect. Also, you need to know one date: 1953. If it’s before 1953, the image will be about the same as a standard TV set.
Finally, you should be careful with Kubrick. He was very concerned about having his movies seen the way he wanted you to see them, and not some other editor who was making the copies. So, for example, Full Metal Jacket was shot with a 4:3 ratio, but very carefully. So in the theatrical release you could cover (matte) the top and bottom of the frame and still get a pretty movie. The fullscreen version of this movie actually shows more than the theatrical version, but both were the director’s intended image.
This tells me nothing. The film was made in 1951 was widescreen (16:9) available then? If not 16:9 what would the aspect ratio be?
