I read Gabe's thread for the first time. Thanks for posting the link!!

Regarding your questions: I am sure wanted these answered indirectly through HHs and in depth discussion rather than direct answers but I thought I'd give my 2 cents anyways.

1. Does Gabe's concept apply to cash games? If so, when and how?
It applies more to cash games imo, where we are playing deep stack poker much more often. In tournies we are thinking more about the rising blinds and are pressured to build a big stack quickly. In cash games we want to make the highest +ev play possible. His post showed how we often should not bet even when we are pretty sure we have the best hand in order to induce a bluff and raise our expectation on later streets. Too many people waste their biggest hands by betting people off of slightly less big hands early on in the hand.

2. Does Gabe's concept apply to non-3bet pots?
I assume we are talking about being flatted by the blinds while raising in position... because we usually want to 3bet KK to isolate.. of course sometimes flatting with AA/KK is okay to mix things up and confuse our opponents.

In non-3bet pots ranges are wider so the chances of non Ax hand being ahead of us increases. But I feel the principle still works... except now middle pair hands might pay us off on a later street as well. The concept remains the same.. don't bet if only better hands call and worse hands fold, on a dry Axx board with a big pair.

3. How should Hero react oop?
Things are always more difficult oop. So we are in the blinds with the villain flatting. It all depends on his flatting range positionally adjusted. If he raised utg I am much more likely to be thinking "AK/AQ" than if he flatted from the button.. there he could have anything depending on our image and his laggyness. I think checking the flop is still the best play, but am more likely to float with a more late position villain.

Note: At micros floating oops seems to always be spew for me. I think Gabe's concept applies much better to thinking opponents.