Oooooooooo.

I like how you think.

But given that my premise is essentially "but what if He didn't step in" this isn't really relevant.

So your actual argument is not that Harry would never pick up a coin in the circumstances stated in my premise--it is that my premise is ludicrous and invalid.

It seemed to me that your premise wasn't that Michael wasn't coming (after all, you mentioned Michael); it was that there was a delay and there was an actual fight that broke out, and the heat got turned up.  My actual argument IS that Harry wouldn't pick up the coin in those circumstances - I pretty much made that my closing statement.  I stand by that. 

If you want to argue "What would happen if TWG wasn't going to save Harry or Molly at all," that's a completely different argument, because in Proven Guilty, Dresden's second-guessed TWG's plan perfectly.  That implies that TWG's personality and motives are different.

If TWG was actually fundamentally different than he is portrayed in The Dresden Files, that would then mean Dresden is fundamentally wrong in his estimation of TWG's motives.  That would mean that Lasciel would be aware that Dresden is incorrect, as she knows TWG far better than most mortals.  That would mean that she would be far better able to argue, convince, and manipulate Harry, arguing from a correct standpoint rather than an incorrect standpoint.  That would mean that, whether Harry would have accepted the coin or not, it would have been based upon a hypothetical situation in a hypothetical universe that does not in any way reflect how the series is actually portrayed.

I try not to get involved in discussions like that.  Starting your premise being "what if X character was different than how he/she is portrayed" is relevant for fan fiction, but not so much for logical discussion.  And yeah, I guess, if that's your posed hypothetical statement then I'm going to have to bow out - not because "it's ludicrous and invalid," but just because my only valid contribution is, "Well, that wouldn't happen, because it didn't happen."

Oo!  People are actually interested!
OK, so I'm going to reply to your points, Slowpool - and I figure that at the same time, I'll probably cover what Kbrizzle was curious about.

•   [Malcolm] - So far, we've only seen Carmichael, Papa Murphy, and Sir Stuart halfway.  I'm not sure that being in Chicago Between has anything to do with either not being good enough or bad enough for What Comes Next, so much as it has something to do with having a will that's not satisfied with being done with the mortal world.  And at the moment, Chicago Between is the only force we know of that holds deceased spirits which also acts to counteract an enemy but has its actions restricted.
•   [Cowl] - No.  In fact, Harry *never* really remarks at all about either's physical appearance.  Neither tall nor short nor fat nor thin.  Which is really, really conspicuous for a PI that notes EVERYONE'S physical appearance.  My best guess is there's some sort of magic protecting him from noting it.  However - Dresden is ALSO able to identify Cowl *at a glance* later on, so presumably he's subconsciously aware of his physical appearance, even if he's not consciously aware.
•   [Mac] - *taps nose*
•   [Andi] - Really?  To the person he's extremely angry at and wary of?  You think that Butters is going to sit down and have a heart-to-heart with the person who was too gosh-darned important to let him make sure his girlfriend wasn't bleeding into her brain after getting a concussion and being stuck under freezing water for so long, and then left Butters and co. to fend for themselves?  You think that he wants to open up to Dresden about how he pretty much made his girlfriend a vegetable and make him pity Butters?  Or worse, not? 
I'll tell you what I see - I see Andi being extremely injured, getting hit on the head, being deprived of oxygen, and the only person at the end of Cold Days who needs to be rushed to the hospital.  She's not talking.  We never hear how she's doing.  In Skin Game, she's always out of the room, out of sight.  She doesn't help Butters in any of his activities, even though she would be far more dangerous and more capable than him, even in his Batman-mode.  Better able to spy on Dresden, too.  Her absence is EXTREMELY conspicuous, given the dire condition she was in a the end of Cold Days.  And none of Butters' dialogue implies anything of Andi, other than that she's passively somewhere, waiting for him.
•   [Ebenezer] We don't exactly know how Nemesis transmits from person to person.  Presumably, it's not something as communicable as a normal disease.  There would, after all, be no reason why it needed to try to manipulate Lily and Fix if Maeve could have infected them just as easily.  With that being said, you're correct that Nemesis would have recognized Harry as a threat, even if Evil Eb didn't.  So I'm backing off on him being nemefected.
However, I don't believe for a second he's not still lying.  He pretty much says so at the end of Changes.  That's twice that he's concealed something huge and important and critical to Harry.  Lies by omission are still lies, and Eb DID say in Blood Rites that everything was out in the open.
•   [Merlin] I wasn't aware of that WOJ.  Can you point to it?  My reasoning for why Merlin was speaking in something that Harry could recognize as British was due to Merlin purportedly living backwards in time; i.e. "born at the wrong end of time, and I have to live backwards from in front", per The Once and Future King.  It makes sense for why something that sounds mostly normal and human would be understandable.
•   [Vadderung] - Not sure, to be honest.  But the being Odin is not well-known for being a nice, kind, helpful old soul.  He's an extremely complex character, and while Loki is the characteristic 'trickster god' of the Norse pantheon, Odin is also a trickster and not 100% good.  Yet, he's the only side character who has ever appeared to be 100% benevolent to Harry, offering advice and services and aid without requiring anything but a nickel in return.  No one gets a free lunch, and Harry and Vadderung aren't friends.  He's in it for something.  I trust Grey's wary attitude towards Vadderung far more than the All-Father's general pleasant demeanor.
•   [Amoracchius] - Cool beans.
•   [Mirror Choice] - To be honest, it's nothing more than a hunch, and far less developed than any other idea that I've listed here.  But as far as I can reckon, it's the one decision that Harry could have made that would be at once more good and intending positivity (i.e. being honest with Susan) but would have had far more disastrous consequences.

I disagree with this "what Lash should have done" routine.  If Harry was any other moral - ANY other mortal that Lasciel had seduced in the past - this would have been the knockout blow.  Lasciel is presumably intelligent enough to have deduced where this trip is ending up.  Running Little Chicago is possibly the least dangerous of all the things Harry is about to attempt, and it's going to get his head blown to pieces.  Lash *knows* that she's not going to get anywhere with the "let me slowly guide you" routine - she NEEDS to offer him the coin.  She does his best attempt, and he refuses - and by doing so, accepts that he may die by his decision.  There's nothing else that she can offer.

If Harry didn't accept Lasciel when Molly was being tortured to death in Faerie, I don't see him suddenly changing his mind because everything's suddenly immediate.  That would imply a decision that was only half-heartedly thought out.  Harry is 100% behind his decision.

The situation you pose is if suddenly there was a battle that broke out in the middle, when the Merlin declared Molly guilty.  Yet I don't see this as being any more hopeless of a situation than storming Arctus Tor, or fighting Eldest Fetch - in that they are completely hopeless, save for information that Harry doesn't have - that he has Summer Fire, or that all of Winter is away.

Lastly...  I feel like you're completely forgetting about Harry's last gambit - that this is, in itself, a leap of faith.  Harry places his faith in TWG, even if he isn't willing to really admit it to himself, that either he had the power to bring Molly back or that Michael was somehow involved and would appear.  When every situation got grimmer - learning that the Merlin had all the votes, that his defense of Molly was over-reaching, that the Merlin pronounced Molly's death - he got more resilient and audacious. 

I mean - there's absolutely NO reason AT ALL to demand that everyone must wait while the Gatekeeper makes his last vote.  The chances against something suddenly changing in the few minutes it would take would be trillions to one.  Yet Dresden DOES demand this, and they DO wait...  not because this is the only option available to him, but because Dresden actually has faith that TWG will pull through.

To think that things might suddenly get a bit spicy, and look dire, and Lash might do her time slowy thing, and Dresden might think, "You know, screw it, this faith thing seemed like a good idea, but I might as well turn into a monster after all to rescue this kid who CERTAINLY will turn into a monster without proper guidance, which I can't provide anymore - THAT is contrary to his character.  Because the more dire things look, the more certain Dresden is that those doors are going to burst open and salvation is on the other side.

Kill Lucifer?  Why would Nicodemus want to kill Lucifer, when it's clearly TWG that he's so bitterly impassioned against?  Furthermore, why would Lucifer help Nicodemus in Small Favor, if Nicodemus has ever displayed any issue at all?

Not arguing against you, per se; I just love twisty theories.  Straight and narrow ones generally don't have a chance of happening.

He'd rather die, yes. But would he rather allow innocents to die? That's why he started working with Lasciel's shadow in the first place, after all--it was the only way to save innocent lives.

Yes. That's exactly why Harry doesn't take up the coin when Lash offers it before running Little Chicago. She poses the same exact dilemma you're doing now, and Harry refuses.

Personally, I think that Lash doesn't make that offer here because she's not particularly well integrated into the story in this book. Proven Guilty was supposed to be before Dead Beat, after all, and in my opinion the Lash storyline shows it. (Except for the end conversation with Michael. That was excellent.)

This is poor reasoning. You're saying that Jim left a huge gaping hole in his story because he was originally planning on a different order, and just didn't make the continuity work out. No. He clearly established why Harry wasn't using Lash to do any death-defying feats.

No. Harry's proven several times that he would rather die than succumb to that power, and especially in Proven Guilty. Besides, if Dresden suddenly had to fight all the assembled White Council at the end of Proven Guilty, I'm not sure that even Lasciel would have been able to save anyone. Presumably, Lash knows this, which is why she doesn't use it as an opportunity.