I agree that fearies using fearie magic shouldn't have to worry about consequences from breaking the laws, But emissaries of power should still be beholden to them (especially the sidhe knights, since part of the reason they exist is that they ARE mortal, and have mortal souls), not to the White Council, but to the internal twisting (and therefore the effects of the Lawbreaker power).
Loyd Slate broke the laws constantly, and he was a pretty twisted (and therefore negative refresh) character
I don't see how the source of the power really makes a difference. They are mortal, they use magic. Therefore the ways they choose to use that magic effects them. A case could be made for them to be given a "Free Pass" to actions taken due to Compels by their Patrons Agenda (those actions being forced upon them, and not their choice). But I wouldn't even give them that much, They wouldn't have those compels if they weren't using their powers, They effectively signed on as their patrons hitman. And the fact that the full ramifications of what they signed up for weren't spelled out isn't an excuse. They took the payment, now its time to pay their debts, and its nobodies fault but their own.
plus the theme of the books, and the RPG seem to lean in that direction as well.
As far as I'm concerned, if your character is definable as human, then it doesn't matter where his Magic comes from, hes beholden to the deleterious effects of Black Magic.
There are some possible instances where an argument might be made that the character isn't "really" human Such as Kincaid, whatever he is. But we don't have enough definitive information to make a good judgment call on that... and he doesn't have magic anyway so it doesn't matter.
Actually I was under the impression, that this is an limitation of the Queens.
Not the peasant fae's.
Shh.. It's a secret and secrets have power. At least make a trade for that info.
One example of "empirical" evidence is that trolls have been snatching (and eating) children that cross bridges for centuries (however the rule now requires it to be "naughty" children). See Restoration of Faith
(Technically this has been out for a long time, but some people don't collect the multi-author anthologies. So buy "Side Jobs" when it comes out in January, it has all of the short stories. Plus "Post-Changes Murphy Sans Dresden.")
Faeries can kill you. Breaking faith with a faerie (or owing a debt without a payment plan) counts as them having direct access to you (sort of like if a wizard had your blood or true name).