Ralif Redhammer
Legend
I've learned never to make absolute statements about particular rules in AD&D. Whatever the specific rule is, you will always find some person, somewhere, who used it.
That said, I am confident that no one has ever played with all the rules, simply because it's ... impossible. I don't just mean ... like, really hard in the "turn every single combat into Campaign for North Africa" way. I mean ... impossible in the sense that there are actual conflicts in the RAW that preclude playing with every single rule turned "on."
At a minimum, house rules need to be effectuated in order to allow certain rules to interact with each other.
Anyway, whenever I've met someone who says that they played with "all the rules," I've quickly learned that they didn't actually mean "all the rules." In fairness, most people haven't played for forty years, and memory is a helluva thing.*
*A lot of people, for example, conflate 1e and 2e, or don't remember how insane some of the RAW in the DMG were.
And yet, those conflicts, the shambolic, occultic nature of AD&D is a huge part of its appeal. There was a sense of mystery and lore about it. You had to delve, divine, and customize the game to run it. Because, as you said, you could not run it completely as written.
I remember trying out the Chance of Contracting Disease and Chance of Contracting Parasitic Infection rules. I think those lasted precisely one session before everyone at the table said "NO!"