Probability manipulation only goes so far against a constant passive effect.

I'd disagree.. energy expended would be greater than energy naturally flowing. Depending on his technique and efficiency, it would simply require upkeep. He directly effects the Haunts by expending his energy upon them. Or to try to put it in physics, if you apply a force against gravity you can resist gravity, how far and how long you resist it depends entirely upon the methods used to do so. If he can directly exert his will upon the situation he must simply apply the right amount of Dv(thrust) in the right quantity for the right amount of time. Gravity is a constant, a passive effect. Unless they become agitated their effecting tech would remain a constant as well. Look at what harry did in DM, he held it back like a dam and when he let it all go it all flowed out at once. Surely if a few well placed tables and lights can do it, mouse wouldn't have any trouble applying the same technique to similar effect without directly fighting it, just making it flow more smoothly.
And hiya TCF!🤗

Ooohh dear me we arrre in trouble 😁
It seems my theory that his Lab and LC survived came to pass and it didn't go up in the conflagration or blow up when LC released it's energy. 😈 This made me very, very happy...
Harry winning the BFS from Marcone would track up as a nice parallel to Merlin winning Edinburgh btw...

Other than a few Mainstays most of the signatories didn't really show themselves it seemed to me.

In theory, yes? The Murphyonic field has interested me a great deal actually.. I think it has everything to do with the source of Wizardy. Namely Luck itself. If your consider wizards only effect technology, and Ghosts can freely effect technology as well, it becomes a byproduct of their aura. They effect technology because they can effect fate, but since they aren't supposed to by cosmic standards, it manifests as effecting technology. Note that every Law has a direct implication on using magic to abrogate the free will of another. An what's more, the superstition around the souring of milk/leaving it out, was that it attracted spirits which supposedly caused bad luck and focused it into the milk. So wizards souring milk was almost literally them expending their effect into a foci for it.

This, is a complicated topic, so excuse me for thinking out loud a bit.. outsiders likely have different varieties and levels just like fae and other supernatural creatures. The Sidhe who are basically humans subsumed by mantles seem to be those who possess physical bodies upon death, but those same Sidhe also seem perfectly effected by a good ole magic circle without the extras. EK is a perfect example of this. He has by Woj the same level of mortality/power level as Santa, whom we know is just mantle. But then we have creatures like the fetches who clearly have no underlying body left when killed... But THEN we have the spiders from TC who do have physical bodies...I actually think the fetches were a special case, being older and more raw then your typical fae.
Angels I think come in two forms, the standard, incorporeal ones. Who I surmise are basically those who've died and found a spot in the heavenly order of things, and Archangels, who died but somehow did not stay dead, being possessed of both a human and an ethereal Grace, like Uriel(this is my line of reasoning on TWG>Jesus<Uriel btw). The Fallen are not Archangels, though perhaps they used to be, Lasciels "nearest to true form" being a Greek woman, Implies that before the fall that was whom she was underneath. Exactly what changed, I'm not sure. But by the same token,(hehe) the fallen now only act through the human host, this somehow Implies to me they are not complete without them. Lucifer I feel sure has a body underneath.. note, that Uriel (or maybe confabulating it with Woj) says they have precisely one choice, and going against cosmic law would make them fall, but they could still do it, Where as Lasciel seems to think they have no choice, she cannot on her own rise, and Lash only did so by, coopting human willpower..

Random tangent, if almost all supernatural creatures, residents of the NN and beyond, are considered on the scale of ghostly beings, then like ghosts, they are not supposed to interact with the natural world without it corrupting them. An I think we've seen that those who do all manage to do so by coopting human/ or at least mortal, will somewhere along the line.

Outsiders are simply the final layer, those things that are not only dead and gone, but forgotten to the point of non existence which they have somehow embraced as a crooked form of existence. Ghosts/zombies are reanimated by filling the impression they left behind, I think, as per Leah in GS, the universe has an impression of them left over echoing through existence that they are trying to fill, this is why Sharkface is described as not bigger than Mab metaphysically speaking, but infinitely deeper. He's so much older it's like comparing Sue to a basic old zombie.(although a zombie to an older zombie may be more appropriate) The impression is still the same size, it's just much deeper and ergo able to be filled with more, eventually.
So your typical outsider has no body, but Walkers I think were on par with Archangels, they used to have it and they want it back.(also outsiders need a human to give them the ability to be here, coopting again..) old Woj someone asked if Sharkface was what was left of Vittorio's body but Jim said he'd wished he'd thought of that. But that implies more human will to exist and take action. I think Walkers are looking for a living host that can bear them, someone they can Ride like the fallen do... And I think those who can do so might happen to be starborn.. at which point, walkers become Riders... I am momentarily spent of thoughts on the subject lol
Short answer, no. we just don't actually understand the rules well enough yet.

There's also that bit from Grave Peril: Lydia, the Cassadra's Tears gifted cult member/victim of Kravos.

"Fire," she whispered. "Wind. I see dark things and a dark war. I see my death coming for me, out of the spirit world. And I see you at the middle of it all. You're the beginning, the end of it. You're the one who can make the path go different ways."

We assume that's fulfilled by the end scene in Grave Peril. What if it's not? Dark war. What if it's about what the books are rapidly approaching?

Oooo, I almost forgot: There's the dreams all pregnant women have in Changes. I'd have to check, but isn't it the same imagery?

I think the Dreams in changes are a Mandela effect of what would have happened if Maggie had been sacrificed like they'd planned..

I've long thought Thomas infected by Nemesis, ever since he ate Justine's insanity with most of her life force. Perhaps he was offered a deal through said infection?

That would imply Lucifer is in the Well, as Uriel was allowed to act in balance of what Harry described as Lucifers power. Or do to mean they used it in some other way? The first time they tried the symbol it wasn't on DR either.