Bit late in jumping in on this, but what the hell...
1. We have been told that Nicodemus has a very specific target in mind, ostensibly kept in the Labyrinth of Daedalus. What is Nic trying to get his hands on and why?
This is such a tough question as there several great possibilities.
I'm going to throw the Seal of Solomon out there for a number of reasons. Chiefly because it confers the power of control, and Nic is all about controlling the circumstances of engagement. Given he is also mostly immune to physical damage (barring running into someone else as savvy as Harry), a relic that acted on a primarily physical scale would be of limited appeal. Also, I'd see Nic as being very, very keen to make sure an item that could potentially bind or control Anduriel in some form got neutralised, but one that allowed him to directly attack hostile Denarians (and possibly help against outsiders) would be something he'd want to get into his possession as soon as possible.
The other guesses seem awesome, though. Wouldn't be surprised if I'm dead wrong.
2. Nicodemus apparently called in a marker from Mab to get Harry on the team. Does he have a specific plan for using Harry or did Mab twist his request? Which of Harry's capabilities will he admit to needing, and (given that this is Nicodemus after all), which abilities is he scheming for Harry to use?
Nic always has a plan, and he rarely fulfils only one objective with a single stroke. Reasons for Dresden:
-Soulfire: First and foremost. Panorama's theories are good.
-The Warden: He can access Demonreach. I don't know how this is crucial yet, but it will be. It's possible the Island's Way opens up straight to Tartarus given what Harry has imprisoned down there.
-Was Dead: Maybe this will help confuse Cerberus. And that's a HUGE maybe. Prolly not. But at least he won't brown his pants about being in the realm of the dead like a typical wizard
-Starborn: Kumori will likely be on the crew. If you were planning on having a Necromancer on your team with links to a big time mage who's worked with outsiders, having a Starborn there as a balancing factor would be a really great threat. Particularly if said Starborn had their last big plan go kablowie.
3. Jim has mentioned that the book will be "Ocean's Eleven". Who else did Nicodemus recruit? How will they interact with Harry?
-Anna Valmont. Nicodemus will have serious leverage on her to bring her in, possibly with her now bearing a coin. More likely, I think it will be blackmail, intimidation and the possibility of a payoff.
-Shagnasty. This one isn't really a guess anymore.
-Kumori: Many have said it, and it makes perfect sense. She can commune with the dead, Harry respects/is creeped out by her and she's shady.
-Binder: Cheap muscle in bulk
-Deirdre: Duh
-Gard or Hendricks: One of them grabbed Namshiel's coin. If the target was the Seal of Solomon, they'd have a great way of binding a demon (theoretically). I'm betting Gard will be in, but who knows.
-Mavra: To piss Harry off. And because she probably could sneak by Cerberus.
-The Redcap: Cheap muscle who hates Harry? Cheap FAE muscle at that? Right up Nic's alley.
4. Harry's general method of operation is to call on his friends for help. In this book, Harry is (initially) allowed one extra backup member on the crew. Who will it be? Which of Harry's other allies will "interfere" before the plot is over?
Kincaid. To summarise:
-Bar Michael, he has the biggest individual Denarian frag headcount of any single character. Based on ONE encounter in the Shedd. This ignores what he may have done in past centuries. To paraphrase Harry in Small Favor, "He's here to help build trust... I can kick you a lot farther with him around."
-Harry wouldn't get all cut up and emo if he dies. Given the choice between Kincaid, Thomas or Murphy, we all know who he'd rather bid Aloha.
-He's totally amoral. If they have to do anything grey or genuinely evil, he won't question it, having given his word, he'll just do it.
Sanya and Murphy will definitely interfere, Michael's "Coming off the bench", Bob will surely put in an appearance and we'll probably see Molly at the end, briefly, when it's time for Harry to be cured. And she'll prolly be damn scary.
5. This is a Denarian book, so (unlike the last "end of the world" showdown), the Swords will almost certainly be present. In fact, there have been various hints... Which Sword wielders will appear in the next book and how will their interference/help affect the plot?
Hopefully Murphy will finally freaking take up Fidelacchius. That one's been coming for a while. My gut says Sanya will get the snot kicked outta him, and this will be a trigger point for her. With the only active knight taken out of play, it literally is up to her to put the boots on and kick major ass.
We know Michael's coming off the bench...and as much as I hate the idea, I think he may end up playing a martyr in this book, having one last fight with Amoracchius. I so hope I'm wrong about that.
6. Mab is apparently against Nicodemus succeeding in this heist. In Cold Days, we found that Mab had complex reasons for wanting Harry to kill Maeve. What are Mab's reasons in this book? Is it simple thwarting or is there something deeper?
Mab's reasons are rarely simple and like Nic she's a big fan of achieving multiple goals with one action:
-Stability. What's the point in defending reality if anyone who might chip in to fight during the BAT is taken out of the game or ganked by Nic's machinations? Mab may not care for personal damage sustained by his victims, but the stakes are too high for her to let Nic screw with the mortal or supernatural order on a big scale
-Enforcement. The Unseelie Accords are Mab's Accords. Anyone with the nerve to violate them has delivered her a personal insult. This is on top of the personal insult delivered by Namshiel and the Black Council in attacking Arctis Tor. We can bet that more of Nicodemus' former allies will have been involved in that attack, Tessa and Rosanna being likely suspects. Mab wants Harry to send a message. Given the acid marks on Arctis Tor, Shagnasty may also have been involved. Mab will want Harry to see its nutless carcass maimed.
-Binding. First Lea, then Maeve, now Cat Sith... if Mab could get a hold of an item capable of binding Nemesis, that would help fix some headaches
7. At the end of Cold Days, Harry needs to stay on the island to keep his growing headaches at bay. The start of Skin Games implies that those headaches will need to be resolved by the end of the book. Who or what is causing those headaches, and how will the whole thing get resolved by the end of the book?
My guess is that the parasite is the residue of Lash's Spirit and an attack by Nemesis. Nemesis infected Lash, as it were, while she was taking a "Psychic Bullet" for Harry at the end of White Night. This would explain the paradox that Nicodemus was entirely unable to command the "shadow" at the end of Small Favor, but how the "Shadow form" shown in Ghost Story knew him so intimately....it's not just Lash/Lasciel anymore and doesn't really define itself that way. Somehow, whether through Lash's actions or through Harry being Starborn, perhaps a bit of both, his mind was insulated from direct infiltration by Nemesis... but the portion of his brain where Lash resided was not. And now it wants out of his skull. If it can't control him, it wants independent existence.
My guess is Molly will have to "remove" this portion of his mind with neuromancy, because while it's separate to him, it's still encapsulated by his mind and insulated by his thoughts.
8. One of the key components of the "Ocean's Eleven" movie is that there is a final twist/reveal. Given that we've got Nicodemus, Harry, Mab, and potentially Hades (and who knows who else) all trying to get the better of each other, if there's one thing you can count on it's some sort of last minute quintuple-cross. What will be the nature of the twist and how will it all fall out?
Panorama's guess of Harry purposely attracting Hades' ire seems right on the money to me. Otherwise he might have Cerberus snap someone's head off. Maybe both. But he'll be super sneaky and use his environment, for sure.
9. (Extra Credit) There are many WAG ("Wild A$$ Guess") theories on the boards, some crazier than others. Write up to three WAG theories (or make up your own) you believe are correct that will be confirmed (or at least have evidence in favor of) in Skin Games.
We may not find out in Skin Game, but a wild ass guess is that the British Accented Prisoner is either Arthur or Merlin. Arthur was supposedly taken to the Isle of Avalon, where his wounds were to be healed and he would one day return (the Once and Future King). Merlin was supposedly imprisoned by the lady of the lake, trapped in walls of air that appeared like a tower to him.
Arthur, if he ever returned, would be a kick ass wielder of Amoracchius in the BAT. Conversely, Merlin's act of sacrifice might be what holds the prison of demonreach together in perfect multi-temporal/dimensional harmony... because it hasn't lost any power after thousands upon thousands of years. No matter how much juice you can sling around, that's a helluva feat.
10. (Extra Credit) This is that "free form" question where you can come up with anything else you think will be in this book. Specific quotes Harry might say (will he actually quote Ocean's Eleven? The movie will have come out already in Harry's timeline)? Tidbits about the White Council? The fate of Molly? Write down anything you want. Note that whatever you write must be specifically mentioned or hinted at in Skin Games in order to be worth credit.
Dresden will most definitely be imprisoning at least one nasty under Demonreach. My bet is on Shagnasty but there's no question that at some point on the island, him and Albert will kick some serious ass.
Molly will be...scary. While there's no question she's better equipped to handle power now than she ever was in the past, she still has self control and impulse issues. Now that she has a ton of power and no real need to show much in the way of contstraint... well. After going through Mab and Lea's school of hard knocks and being a grade A mind bender, no one will want to mess with her.