Maybe the planet name relates to "earthy", opposite "skyey"?
No, it is pronounced like Bugs Bunny, per Gygax.
So, "oy earth". LOL.
Yup: Greyhawk is whinsical, more than it is gritty: see also, the demi-god Planeswalker who looks like Clint Eastwood duel wielding six shooters.
Yes, all of Gygax's AD&D modules were set in Greyhawk (albeit...lightly), and the 1983 box set has a canonical location for all AD&D models published up to that time (which match their locations of the 7 major Dungeons on this new map).
1e-style is more like defacto "homebrewing" a unique setting, by the fact of running each adventure in isolation, and then realizing the constellations between them.
Wasn’t Keep on the Borderlands written to be setting agnostic and later retconned into Grayhawk?
Well, Keep on the Borderlands was a BD&D module...and not to get too into the weeds about TSR's absurd brand management in the era of excess, AD&D material was by default set in Greyhawk prior to 1984 (when Dragonlance dropped), and BD&D material was not set in Greyhawk. The not-Greyhawk of BD&D evolved into Mystara over time, so it is not incorrect to say that B2 is set in Mystara by default (because it follows Basic assumptions instead of AD&D assumptions), even though it was published before the Kent State graduates put their home campaign into B/X.
Sorta, yes. It originally was setting agnostic. At least one printing of KotB offers a suggestion of placement in Greyhawk. But seeing, that the module was released for the "Basic" line, it was later retconned into the Known World (Mystara) with the release of the Expert Set.
