Maybe a ritual to give the aspect "Borrow Love" or the like, perhaps requiring that you find a participant who actually has true love for another.

True Love will protect you from the Raiths, and from the Lust that they typically incite.  It will not likely protect you against Despair, unless, perhaps, incited by a (deviant) Raith.

I think he's saying that human SOULS are special snowflakes, rather than merely humans in general being special snowflakes.
It's not really any less arbitrary, though.

Accidental Hexing is the product of Compels, and nothing else.  Immunity to it is not worth refresh.  Compels are cost-neutral.

Pretty sure the same can be said of 'Were-Trousers'.

I suspect Sniper to be rather more powerful than stunts should be, but I'm not certain.

By 'incredibly humanocentric', I mean that it is even more humanocentric that would otherwise seem to be the case.
It takes an impressively humanocentric cosmology, and makes it substantially more so.

True. But Im talking of more...natural? things. Like animals or plants. I can wrap my head around faries and undead. Other earthly creatures makes less sense to me, though the imagination bit might have something to do with it.

If working under the assumption of blackstaff's theory, mundane non-humans would fall under the category of 'byproducts of creation'.
This theory is incredibly humanocentric, but hey, maybe that works for your game.

Vampires [...] can, but they leave their power at the door.

Except BCVs, who have large amounts of power tied up in animating a corpse.  And maybe RCVs, who are properly demons of the near Nevernever.

The only thing I'd add to that is that there are many behaviors including some uses of magic not addresses by the Council's Laws which can corrupt the individual.

Source for this corruption being anything on par with that addressed by the Laws?
Or happening at all in any meaningful way?

More than just personal theorycrafting, here, please, as I've already seen that on this (and related) thread(s) with regards to this subject.

The commandments and prohibitions of the Laws are creations of the Council.  The Truth of the Laws exists independently of any mortal agency.
Phrased as their metaphysical Truths, the Laws might appear as 'Will not [these results] by magic, lest you be tainted in your soul'.
Or, without the judgement that such tainting is a thing to avoid, 'Will [these results] by magic and be tainted in your soul'.
(this phrasing obviously doesn't cover the 7th law, but that is a special case among special cases)