OP, the thing is, you can play 40/10 at 2NL and crush it. Someone mentioned seeing lots of flops and getting players calling 40bb later in the hand with crap, but the truth is more like people calling 200bb with crap. It would not surprise me if a skilled player could play close to 100% vpip and be profitable at 2NL. It's that bad. The problem comes when you decide to play anything other than 2NL. Even at 5NL you don't get paid off as insanely well as you do at 2NL. I think by 10NL now you need a fairly agressive style to do well, or you need to be exceptionally talented and single-tabling.

dismal - I look at a fat/thin value as a spectrum: On one side (fat) you have the nuts, where by definition 100% of the time you are called you are winning. At the other end (thin) you have a hand where you it is slightly better than 50/50 that you are ahead when called. At the thin end of the spectrum, you also have the problem of putting your opponent on a range being an inexact science, so there is risk that your thin bet isn't for value at all. In any case, I think the best examples of thin value are on the river, where the draws have missed, and you have to figure out which stupid pairs Villain is going to call with. Like in your first example, if Villain only calls with pairs on the river, most river cards really hurt Hero's equity. My reading of Sircuddles post was that he was basically okay with thin value bets, provided you do the appropriate handreading and decline to bet when it isn't really for any value anymore. But I think the way he used the term "thin value" was confusing, to me it is more like what a lot of people would just call spew.

I also think that Sircuddles concept of bad slowplaying was pretty narrow - my guess is that he'd agree with what you said in your post about using a good hand as a bluffcatcher against an aggressive opponent on a dry flop. What I think he was criticizing was slowplaying against passive players (who would call if Hero bet with his monster), particularly on drawy board (which give the calling stations more reason to call and create the risk that Hero will be outdrawn).