I also got the rescheduling screen.  Guess I'll have more to look forward to!

1 ) Harry usually has a few supporting characters in each book.  Who do you think will be the main sidekick in Cold Days and in what way will they help?  Who else will have a significant contribution to the plot?

Toot and Cat Sith will be Harry's primary companions.  Although impressive for a dewdrop, Cat Sith will find Toot too far beneath him.  Molly will have a significant role.  Murphy's role will be limited.

2 ) At the end of Ghost Story, Harry has said goodbye to all his friends in Chicago. 

a. Who will be the first friend to find out Harry isn't dead? 

Bob will find out first, and through him, Butters.

b. What shenanigans/snark will Harry use when he "re-appears"?

He will quote Gandalf.  He will also quote Princess Bride, and Monty Python ("I got better!")

c. Who will have the coolest reaction?

Molly will get so excited her camouflage reflex will kick in, causing her visibility to vary in degrees, along with her hair color.

d. Who will have the most touching reaction?

Thomas, who will try to act nonchalant but fail.

3 ) In nearly every book, Harry usually comes up with a new powerup/tool/way of making things go boom.  Given that he just became the new WK, what new abilities will he rely on and which new ability will be the most useful to him during the story (and how)?

One new ability which will be significant is his new physical prowess.  The strength and endurance will help in more than just the obvious ways (e.g. allowing steady aim with that rifle).  Ice will be used often, of course.  He will layer protections on a new duster, but make it a permanent charm.  He will not use Fae magic to create or augment any foci.

4 ) Harry generally has a "Big Bad" to worry about.  In fact, according to the blurb, Harry is going after someone very specific.  Who will that enemy be, and how will Harry take him/her/it down?

The Big Bad will be one of the Fomor (not a servitor).  It will be fairly high-ranking, as it has been around since before they were cast into the sea.  Harry will not kill it, due to his thoughts on the aftermath of Changes in Ghost Story and how he needs to consider the longer-term effects of his decisions.  Harry will remove its incentive to continue threatening Demonreach (the source of magic referenced in the blurb).

5 ) Harry usually faces some sort of "Choice" in every book.  A point where the easy way out will cost his soul/humanity in some way. According to the blurb, this book will be no different.  What will be the most crucial "choice" Harry makes?

Harry will allow a friend or ally to be killed or seriously harmed because of his decision to either:
(a) not kill the Big Bad (while not violating the letter of Mab's order), or
(b) follow Mab's orders and kill it.

6 ) As the new Winter Knight, Harry is pretty much guaranteed to encounter his Summer counterpart -- Fix.  What will their interactions be?  Will Fix survive?

Harry will not kill Fix.  Fix will survive, unless he is the aforementioned ally who will die as a result of Harry's big choice.  He will have multiple interactions with Fix, each less confrontational than the last.  Fix will show Harry just how much more experienced he is at Knighting in their first interaction.

7 ) Jim has mentioned that it's about time now to start revealing some of the motivations/dealings of the shadowy figures working behind the scenes (i.e. what Harry calls the "Black Council").  What Black Council secrets/actions will be revealed in this book?

It will be revealed that there is no single "Black Council," but rather that there are at least 2 such organizations working toward different ends.  Where their interests coincide they are not opposed to working together, but there is no alliance.  At least one of these groups is aware of the Grey Council.  If there are 3 or more such groups, one of them IS the Grey Council (though it is working specifically to subvert the other two).

Thus far, these groups have been intentionally destabilizing the balance of power in order to create the conditions necessary to accomplish one larger,  more specific initiative.  The aim of at least one of these groups is to specifically eliminate the Sidhe (as in, all of them (especially Mab)).  The aim of another is to invite the Outsiders in for open-house and tea.  As an Outsiderbane Winter Knight, Harry is now a major target for both of these groups, and the prized member of the Grey Council (though he won't know it yet).

8 ) There are many WAG ("Wild A$$ Guess") theories on the boards.  Write up to three WAG theories you believe are correct that will be confirmed (or at least have evidence in favor of) in Cold Days.

Lash will come back in this book.  She will be a full-on ally/power-up to Harry from now on.  Because her abilities are less limited by Harry's physical body than Harry's abilities are, Harry will have a weaker version of the perfect memory he had in Ghost Story.  Evidence for this will be established this book, but it will become much more pronounced next book.  Harry's new Lash-powered memory will reach back to before he had even picked up the coin, since she will be helping him around his own mortal limitations and not simply remembering things for him.

Cowl has been working for or in league with the Fomor.  However, he has bigger plans and is merely using them as a temporary tool.  We will learn little if anything about Kumori in this book.

9 ) Extra credit:  Write down any prediction about that you think might improve your final score.  Only issues alluded to within Cold Days will be counted.

At some point, Harry and Cat Sith together will encounter Mister.  Mister will smash into Harry's shins as usual, and completely and arrogantly ignore Cat Sith.  This will improve Cat Sith's estimation of Harry.

Marcone will make at most minor appearances in this book, more in the following one.

First, I like the theory, Knnn.

Second, In my pre-GS backwards order re-read, I'm in the middle of PG now.  I've piled up a bunch of questions already, and this seems like a good place to dump some of them (some may have obvious answers, my memory of PG is always hazy since I still don't know what the big picture is.

• In the beginning, Eb asked Harry to investigate why the Sidhe haven’t gone to war with the Rampires for trespassing through Faerie and bringing Outsiders, on behalf of “myself, a few others… people I trust.”  Is this the first mention of the Grey Council?  He refers to them almost exactly the same way he does in TC.
• According to Eb, the Merlin wanted Harry stripped of his rank as Warden, but Luccio supported Harry and the rest of the SC overruled the Merlin.  Why did Luccio back Harry?  Was she already mind-bent a la TC, or was it just because he executed Capiorcorpus?
• Fix warns Harry that their phone conversation might be tapped- “Someone isn’t playing by the old rules anymore.” That’s obviously true for Harry, but why would Fix be concerned about a tap?  Is Fix worried about his end or Harry’s end being the tapped one? 
• Darby Crane (Madrigal Raith) is the Producer and Director of the movie the Scarecrow is from.  Is this evidence of collaboration between them? (if so, that would work against your theory).
• When the magical murk plunges the hotel into darkness, Harry reached out to the cold and gloom and felt a vaguely familiar spellworking, but he couldn’t remember precisely where he’d encountered it before.  It was different from the Myrk in SmF (as you noted), but I'm not sure it would be familiar to Harry if it was coming from the Fetches.
• After blasting the hockey-mask reaper fetch through the projection screen, Harry sees someone flee the room out of the corner of his eye.  Do we know who it was?
• Lastly, Madrigal (Darby) does the Whampire freeze and Glau tenses up when Harry mentions his name to them in front of the elevator with Murph.  Madrigal immediately seems to fear an attack from Harry.  Does he just know Harry by reputation and fear that he'll go off half-cocked and burn down another building, or was he aware that Harry might be on to his plan (whatever it was).  If it's the second, then why did he think he could threaten Harry with publicity?  Wouldn't he have at least done the 0.2 seconds of research needed to see that Chicago's Warden openly advertises his wizardly services?

I might have to re-read this one twice this time.