John F. Some random comments.
1. Since Charles starts by mentioning Japanese technical terms and a historical context, it's worth emphasising that these are indeed worth mentioning. There's a large overlap with thickness, of course, and that alone is subdivided into several types. But in Japan, historically, we can go back to kurai, as first recorded in the excellent advice of Honinbo Sanetsu  in the early 17th century. He points to the defective way of playing called kuraizume?, which effectively means too much influence/thickness. Shisei? and seiryoku? became regular, if rather loose terms, reflecting different usages of the Chinese term shi?, not so much as go terms but as concepts from texts such as Art of War. In old Chinese go commentaries, shi is rather common, but as there is no word for thickness, it can be hard to pin down at times (hence shisei, shiryoku and atsumi in Japanese).
2. There is also the term sphere of influence. I'm surprised Charles didn't mention it as it seems it could usefully be used to separate out some of the points he made about frameworks. It's a newish term in Japanese go, no doubt borrowed from modern geopolitics, but it's very common and should probably be accorded the status of a technical term by now.
3. The billiards analogy is a brilliant addition to the lexicon. (And by no means the first such contribution from Charles). The point about military usage of threat was new to me, and valuable.
4. I couldn't understand what was meant by "bending back."
 The famous part of his advice was that it's best to take a safe win by 6 points instead of going for a theoretically possible 8 points, but the rest of his words are actually more interesting and relate largely to this topic.
Andrew W: My reading of "bending back", especially as counterposed with "snipping off", was in terms of pushing an entire weakish group low rather than trying to cut off part of it (which may allow one's opponent to treat the group lightly. Of course, I'm a very weak 3 kyu, so I may well be misunderstanding).
Charles I should post some more on bending back from 'Fighting Fit', an unpublished manuscript I wrote with Seong-June Kim?. (Which seems to be done by now --Dieter)
Dieter: I added more hyperlinks to this article. If this obfuscates the reading, feel free to restore the previous version.