Ok, thanks again to everyone who has replied.
You have assuaged my concerns about being erroneously banned, so that's very helpful.
I've also been very interested in the questing vs grinding discussion that has occurred in the thread.
That having been said, there's another variable that perhaps I hadn't considered when I posted the OP: mob density.

Now, there are unknowns here as relates to Classic. We don't yet know if Blizzard is going to implement tech such as dynamic respawns or server sharding in order to accommodate high numbers of players in close quarters like starter zones. Both of those things are tech that did not exist in vanilla wow, so they may or may not be used in Classic.

If Blizzard does not implement some kind of tech that makes more mobs available....then both questing and (world) grinding could be negatively impacted if too many players are in a zone. BUT, instance grinding wouldn't be affected at all by low or high server pops. This is another reason I'm keenly interested in the viability of dungeon grinding.