Hi,
If I throw a bey directly into one of the overzones or extreme zones, is the throw valid? If I look at the rules, it doesn't say it must land in the battle zone, but only that it must touch the stadium (which is made up of the battle zone, overzone, and extreme zone).

Yes, it feels counterintuitive that it should count but you are correct in your reading of the rules and it is valid. This is why I use a custom rule at my events that rules these as launch errors. Though I understand why the WBO does not, as a ruling like that can be somewhat subjective.

thank you so much for the answer!
I imagined it was actually like that but I wanted confirmation, thank you very much

It doesn’t exactly count if it goes in before it hits opponent but some tornaments abide that rule

Normally, direct into pocket is full points to the opponent and you move on to the next bey in 3on3/Counter Battle. There is an optional clause that changes this to be 1 point for the opponent and a redo of the current battle.