I have no clue what the above statement says.
I can't go past the Codex??? Does this mean I should learn the Codex? Or not learn more than the Codex?
Then you might consider reducing the salary of your employing for their inability to self-study the codex (j/k). You'll have to find a dev (or two), who really know the wp, and that's the way to go, in my opinion.
Okay I'll pay myself less. We're an engineering business. This means that we have no funds to hire anybody for dev.
This thread was originally meant to reference a manual. These have just become available (in dented hardcopy) from digiWP called "Digging into WordPress" by Chris Coyier & Jeff Starr.