2) Were the Gith and Slaadi creations tied together?
Only tangentially. I mentioned the rather odd multi-GM campaign I was involved in earlier. It’s hard to come up with original twists on something in the Monster Manual if everyone and their dog is also using it for bedtime reading. For this reason, we tended to roll our own. World building has always been an interest of mine; I tended to be more of a game designer than a GM or player, if that isn’t a contradiction in terms. Apropos the Githyanki, the name was lifted from a George R. R. Martin SF novel (“The dying of the light”). I’ve always felt slightly guilty about that, and credit should be given where credit’s due.
3) What was your original inspiration for the githyanki and githzerai? Did they just sort of appear out of the ether of original ideas, or did something else inspire the initial idea? How about the Slaadi?
Well, the fact that I was running a fever when I came up with the Slaadi is probably not going to surprise anyone — think of ‘em as my independent exploration of Lovecraftiana. (I didn’t discover H. P. Lovecraft until a couple of years later.)