>First:
>
>Dio's peanut gallery is reporting sneak failing for thieves
>and assassins. This a new change, something that's always
>been around, or a collective dose of purple crack?

No change that I'm aware of.

>Second:
>
>What stats on the stunner's part (str? dex?) influence the
>likelihood of "stun" successfully knocking someone out?

I'd guess strength, but that's without looking at the code.

>Third:
>
>Same question as above but with cranial. (I know target's
>headgear plays a part, this question is just about the
>cranial-er's stats).

I think this one is more based on skill (cranial & mace & gankiness vs. victims armor)