Is luck a stat that varies, or is it the same for every class/race combo? If it varies, how significantly?

It varies a bit, but not a ton for a given class/race.

Why else would it not be on PBF's even though we are told the pbf's show everything.

Why else would Cyradia have set that transmuter's luck to 1 or whatever if it didn't mean anything.

I bet if they posted luck stats in PBF's we'd see most of the big characters having far higher luck stats than the lesser ones.

But maybe this is just conspiracy talk.

They probably hide it from PBF's for a much better reason, I just have no idea what that could be.

It's just conspiracy talk.

There's an exhaustive list out there of what it effects that I've posted probably a dozen times. It's not a long list.

we know it definitely affects conjure beer elemental by 20%

I love a good conspiracy as much as the next guy, but I don't see one here.