I enjoyed Nick and Norah, and did anyone dislike it for the directing? Or for the story? If so, I don't think disliking Nick and Norah is any indication on how you'll like the director on Runaways.
Speaking of his directing, actually, there are a few scenes that I thought were well handled, specifically when the girl gets her 'big O,' I thought was very artful, but there were other cool moments, such as when the drunk girl in the bathroom, especially when she comes out after they just missed her. The focus on the couple's hands in the 'climactic' scene also was very good to me. The only thing I think was badly done, as a director, was when the couple were leaving the Fluffy concert, it wasn't clear to me that they were leaving, exactly. Character-wise, he knows how to work with late-teens, at the very least, and he knows how to handle the aloof kid, the hipster chick, the jealous bia, the self-interested artist, gay friendships, the party girl, and a couple others. Some of those characters are directly analogous to the Runaways. The female lead specifically is just a softer more musical Gert. Obviously if you haven't seen the film, none of this means anything, beyond that the director does have some talent for highlighting character interactions.
It also makes me wonder if Hollywood sees Runaways as a 'hipster' type vibe, which would be interesting to say the least, despite the preponderance of band references in the Alex-era (lol, era), I don't think Alex, Molly or even Nico really fit into that type of... subcultural framework. At least in my opinion.
Casting? I always hate the casting for movies based on teens, because they always cast near-30 year olds who barely look passing in the first season/movie, much less subsequently. Chloe Moretz, at 13 being cast for an 11 year old is case in point, especially for a character who's age and innocence is a big part of the character. The Official Ages were Chase: 17, Alex, Nico, Karolina: 16, Gert: 14, Molly: 11.
If it were me?
Gertrude Yorkes - Abigail Breslin (I defy you to choose a better actress for this role)
Karolina Dean - Taylor Momsen (Someone suggested her, I youtubed her, she's great:
http://www.youtube.com/watch?v=uMk7pe8FNOA)
Molly Hayes - An Unknown, the next Dakota Fanning
Chase Stein - Josh Hutcherson (RV, Zathura)
Alex Wilder - Tyler James Williams (Everybody Hates Chris)
Nico Minoru - An Unknown
If they can get unknowns of the right age that work, go for that, but there are definitely known actors that can do the job right.
You know what would be super cool though? Getting genre/character actors as the parents as a nod to the concepts represented?
The Wilders are a crime family, so get crime drama actors Chi McBride and Regina King.
The Steins are mad scientists, so get sci fi actors Brent Spiner and Carrie Fisher
The Yorkes are Time Travellers, so get Quantum Leap's Scott Bakula and Sarah Connor's Lena Headey
The Minorus are wizards, so get wuxia actors Chow Yun Fat and Michelle Yeoh
The Deans are Aliens, so get alien actors Dean Cain (Superman) and Morena Baccarin (V)
The Hayes are psionic Mutants, so get telepaths Greg Grunberg and Famke Janssen
That would make me happy, casting nods similar to those.
That's all, thanks for reading.
tl;dr version - Don't cast 25 year olds as teens!