No, it doesn't. It doesn't explain why they target Molly specifically, why her magic was cannibalized by fear bringer or any of a host of issues I have. That's one person's perspective, it does not include everything. It does not explain why I fishy named lady directed Molly towards using fear as a weapon. Michael was speaking more of why he went on a mission when his daughter might need him which is perfectly valid. And that doesn't make sense as an attack on harry, because after all, they just figured out direct attacks do not work as you already said. Doesn't explain the TT background either. It's actually towards how the good guys moved to counter, not the original plan of the black hats.
On the other hand it would explain why Arctis Tor closes itself to Harry mid adventure, scarecrow was eating Molly at that time, once he got to the Nfected bit he changed, which is why he says things like he's been serving the queen of air and darkness since before human memory, which would be before valid existence, things oblivated. The recognition in his eyes, or the "or what follows" Jab which is a reference to HWWBH. Pretty sure there's more im Forgetting.. also if you were to prescribe to the walkers equal Riders theory then him as the headless horseman is also a big cluebat to his real identity, the name Darby Crane is not a coincidence here. Nor are their nature's of eating fear a coincidence I think, it intentionally makes them a mirror for fearbringer.

@morris Your argument is counter intuitive, if they just now figured out Harry won't be directly killed then why some crazy plot to get the job done in PG?
You assume Nemfecting Molly was a plot vs harry, it was a plot against Molly too. Way too many Molly clues for her importance, Leah asking about Michael's first born being one part of that.

And if Lucifer were in fact Nemfected, wouldn’t he argue?

I think Lucifer used to BE the Adversary, that was his role in the heavenly court before his fall, but the only place I can think of him acting in his official role is in Job. According to the kabbalah when he became the devil his wife Lilith became the Adversary. This would track quite nicely with Nemesis and things that get to act in cosmic imbalance.

I think it's a big assumption that Molly is infected.
It was a small favor.

I think it's a very small assumption, warlocks are quite literally replaced by inhuman beings, there's a plot, if not against her(although the case can and has been made for that) then certainly to save her in PG. She's told to use fear while violating free will and Leah changes how she operates by showing her the fae way of using fear without violating the laws, which leads her to become a better candidate for winter lady. Then we have fearbringer who manifests itself from the supernatural fear Molly specifically has caused or fed. It having the functional form of the scarecrow, his height, while wearing what amounts to the ragged cloth described in GS as what is left of Harry's duster which she used as her calling card earning her the name rag lady. I personally think it's a big assumption to think she's not, or that quite clearly more is not going on there then explicitly said.

Nobody else has mentioned his tainted magic since he got mouse, but that's why I say in theory. Since it's part of what he does, I can't imagine him not cleansing harry.

I think Nemesis can infect mortals. I also think your Hounds/Nemesis connection would be a good limiter on why Nemesis can't just infect everyone. It might work that Nemesis needs different amounts of power (viral load) to infect different hosts, so it can infect a Lady or a dozen lower powered Sidhe, for example.

idk, likely Nemesis can come and go in those already compromised,like, they're tainted but not under direct influence or overpowered. I originally thought this from the scene in PG where mouse growls at molly but then just looks confused, Nemesis saw a foo dog and ran like a mofo, after reading zoo day I could see why, Mouse could chase it back to where it lives. That makes him a rather dangerous threat.

Murphy gonna die... Harry mentioned how she'd die to protect this city, forshadowing I'd think..

The you're a wizard Harry line. Such fan service, plus it has implies they exist as books in the Dresden verse AND Harry's read them too lol