Okay, I'm following along with you guys with my falling apart copy, I'm on the second page and I already spot a weird plot hole--how does both Batman and Riddler have the SAME calling cards for each of the killings so far?
Personally, I love the idea of Alfred as being a super badass spy back in the day--especially with little things, like in a recent issue of Batman Incorporated where we find out that Alfred can still beat Bruce in a game of chess.

I kinda have the opposite thing with Sofia's voice--the whole point of what makes Dr. Girlfriend funny is the fact that a such a petite, feminine woman can have that hard, masculine voice. I would think it would work better if Sofia's voice is more feminine, but can have a lot of grit thrown in when needed.
"Fireworks laced with LSD." It's Scarecrow's Fear Toxin--LSD doesn't really work that way. I'm not a big expert on it, but I'm pretty certain you need to orally take LSD for it to work.
Mad Hatter isn't saying anything especially random--from what I understand, those are all stuff that Lewis Carroll, the writer of Alice in Wonderland, had wrote over the years.
"They don't like sunlight."

"How did his teeth turn yellow?" Some acid probably got on them--I imagine acid does horrors for the enamel in your teeth.
"Why is Grundy and Catwoman there?" Grundy became loyal to Dent after what happened in Labor Day, and Catwoman, who's been spying on the Falcones this whole time, is part because she wants in on the Falcone's downfall.
Sale's Two-Face is definitely my favorite take on the character--he's SUPPOSED to look freaky and horrifying. As for the outfit--remember he's been missing for about two months--that's plenty of time to get your own custom suit talored on the down-low, I would think.
The way the book is trying to make it, the killings went more like this:
From Halloween until Christmas, Gilda was the killer. Dent may or may not have killed Alberto on New Year's, but either way, Alberto survived and started doing killings himself, and a lot of his killings became more specific, such as the coroner who would probably know something about him. Finally, Dent was the final Holiday murderer, killing Carmine and Vernon on Halloween.
My problem with Gilda being one of the killers is the Thanksgiving killing--you guys probably don't remember, but during that time, she was still in the hospital after the bombing of their house in the first issue. So, we're supposed to believe that this very frail-looking, injured woman was able to sneak out of a hospital (which, being a metropolitan hospital in one of the most dangerous cities in the world, I would assume would be heavily guarded), get her tools, whack an entire room of Irish mafia enforcers, and then sneak back into the hospital...all without NO ONE noticing? Yeah, it's bullshit, it's Loeb lamely trying to add a twist ending to it.
It really epitomizes my problem with Loeb's Batman work--he creates great characters and their interactions...but the actual mystery story's always crap.
Actually, Tony Daniel's current run on Batman has made The Long Halloween cannon--it brings in many characters from those books, one of the big ones being Gilda Dent in the current arc. She also "appears" in Daredevil: Yellow, also by Loeb and Sale.