On the subject of questions for Old Geezer...
1. Did Gygax actually run with ability scores a la Greyhawk (percentile strength, % chance to learn spells etc) or was that one of the things that was cooked up for publication?
Yes, we used the Greyhawk stuff.
2. Did you ever straight up fight a Balrog? If so, how did it go? Looking back at published stuff from the period it seems like Balrogs were an early iconic monster that sort of got disappeared because the Tolkien estate didn't like D&D using its intellectual property.
Yeah, Balrogs were second only to Dragons as badass monsters. Yes, I fought them, but never single handedly, those fuckers were nasty.
3. Was magic "Vancian" in Greyhawk from the word go, or did Gary tinker with other stuff (like the Chainmail rules for keeping spells)? When did spell levels come into being?
It was always Vancian. What rules for keeping spells in CHAINMAIL? (my copy isn't handy)
Spell levels were there the first time I played.
Also, I really LIKE the OD&D magic system.
4. How early do you remember Good/Neutral/Evil being added to alignment?
The 9 alignments first appeared in AD&D first edition. However, even in the days of CHAINMAIL we used to talk about what was the difference between Law/Neutral/Chaos and Good/neutral/Evil, so the discussion is older than D&D.