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?
Not sure, will come back to this...

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?
This is Nicodemus, he's got a plan alright, to manipulate Harry into doing something that will benefit him in the long run. Something involving the use of soulfire...

3. Jim has mentioned that the book will be "Ocean's Eleven".  Who else did Nicodemus recruit?  How will they interact with Harry?
Not sure, will come back to this...

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?
Thomas is the logical choice, but I'm going to say Lea is getting back into the picture here. Thomas/Molly/Ivy

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?
Sanya will be there to argue against Harry working with Nic, Michael will come off the bench and something terrible will happen to him for his trouble, and seeing as we're going to the underworld I wouldn't be surprised if we somehow saw Shiro at some point. (even if only as a flashback)

6. Mab is apparently against Nicodemus succeeding in this heist.  In the 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?
Not sure, will come back to this...

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?
It's the growing presence of Lash, who has been mostly dormant while recovering from the Psychic Bullet she took for Harry back in WN, her emergence is actually spawning a new soul inside Harry's body and is the reason for the headaches, Molly will act as a psychic conduit for Lash and transfer her into the body of Helen Beckett's daughter,

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?
Not sure, will come back to this...

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.
WAG#1: I mentioned before that Lash is going to wind up in body of Helen's daughter, this is why...she's going to take up Fidelacchius, the sword of faith
WAG#2: Harry will admit to himself that he has feelings for Molly beyond that of a Master/Apprentice and give in to her desire to be with him, only to be caught in the act by Murphy who will be crushed even though she knew it was a possibility (dare I say, even an inevitability!)
WAG#3: Nicodemus will die by the conclusion of events in this book...Dead...D-E-D...and Anduriel will wind up in the hands of the last person Harry would ever suspect/expect....
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.
Not sure, will come back to this...

Nelson, I'm going to have to agree with Tami here on this, the ritual curse that wiped out the Red Court was keyed on the youngest member of a bloodline, which would carry it into the preceding generations to complete it's effect which is why they were targeting Maggie Jr to kill Harry and Ebenezar. But with Ramps it's not so much of a genealogical bloodline as it is a metaphysical one based on how they turn victims into the half breeds like Susan and Martin...the curse worked to wipe out the Reds because at that moment Susan was the youngest in the Red Kings bloodline, and through him it would annihilate the rest. Maggie Jr if anything has a better chance at being a wizard due to her parentage than to have any aspects of the Ramps predator spirit inside her.

Bear in mind that when Harry was about to execute Arianna at the end of the duel, he made note that she was skewered in numerous places by the shards of ice that he directed towards her including the one in her stomach. Unless Arianna could ignore the spike that opened her blood reservoir, (which makes Ramps weaker than kittens), I find it unlikely that she could have managed to attempt any spell against Harry with a single word just before he craters her.