At Amazon Studios
Find Me Online
http://www.facebook.com/profi...
My website: www.jimichelion.com
Find my book at Amazon: http://www.amazon.com/Current...
My website: www.jimichelion.com
Find my book at Amazon: http://www.amazon.com/Current...

That said, the opening scene doesn't work very well because of one simple error. The diner in which the initial hit takes place feels deserted. Empty. It should be a crowded place. Packed with people. Make this change and it suddenly feels right.
In a few of the early scenes, the characters spend to much time saying hello. Unless the hello has subtext (these don't), don't bother. Cut them out and jump into the conversation without it. Also, and this is my last gripe about the way the story starts, I think the idea of a "quick" hit job to a professional hitman doesn't ring true. I doubt there's any such thing as a "quick" hit job to a pro. To a common thug, maybe.
Up until the point when Nick gets assigned as the ride-along to Lou, the characters frankly felt generic. Here's the thing. The script works as humor precisely because the characters are generic. Nevertheless, in these opening pages, you need a little more oomph to show us something more about these characters. Particularly Nick. Perhaps the mob boss can bitch and moan about what a pain-in-the-ass it is to have to do a favor for his nephew. Set Nick up a little better, since he's so crucial to the story. Give him more of a back story.
It might help to play up the whole rushing against the clock to pay the babysitter angle a little more. It's funny for a hitman to worry about this, and it would give a little more impetus to the first act.
Oh, um, when Nick pukes it IS a little out of character (since he's really a pro) and it also would leave DNA evidence for the cops.
Once we get past some of the problems with getting this thing started, it really sings. I had at least four laugh-out-loud moments, and that's a new record for me. In a way, this things screams "independent movie" that gets made on a budget and breaks wide into a general release hit. A little like "Lock, Stock and Two Smoking Barrels".
I think we need a clearer idea (particularly during the long second act) about what Lou cares about most.
I think Lou should know more about Tony's regular haunts. You know, where does he like to hang out. He should check out those places first, and then, when he comes up empty, that's when he should ask around and dig deeper for the secret hideout.
When Lou goes into his own apartment he says, "anybody here?" I should think at this point he'd care more about his daughter, and would call out her name.
The movie quote gag runs dry after the first time. It's a little too self-conscious. You can fix this easily. Make it a character flaw for Lou. He has no real life of his own, so he channels movie quotes as a way to adjust. This makes him a little pathetic, but that's the whole point.
Question: why does Nick pretend to be an amateur after Lou has already concluded he's a professional killer? Example - Nick: Lou, what do I do? Lou: How about shoot them? Nick: Okay.
On page 50, Nick says, "I gotta stick to the head shots." But he's talking to himself. I don't think this plays well. Perhaps if he said something funny to the guard...
The same thing happens when Lou comes across a muscle-man. He says "Seriously?" but is it to himself or the enemy. I've seen this joke so many times, in so many ways, going back to the first Indiana Jones movie, that I think you need something fresher here.
Not sure about Nick convincing the female guard (Tony's daughter) to fight him mano-a-mano. It seems a little contrived. Fortunately he gets his ass kicked anyway, so it works in the end. If she's so tough, maybe she never has a gun? Maybe Nick throws the knife at her, and she catches it, then comes after him bare-handed. I'm just saying it's something to consider.
When Lou traps Tony, why doesn't Tony kill him right away? He needs a better motivation, or less opportunity to kill Lou, IMO.
The line, "Let's get out of here," is probably the most overused bad line in movie history. It's so old and overused that it's actually made it onto a few trivia questions as the answer to the question, "What is the most overused bad line in movie history." Try to think of something better.
When the tables are turned, why doesn't Lou kill Tony when he has the chance?
Final gripe: Lou wasn't present when Nick whispered something in his daughter's ear, so Nick cannot credibly refer to it when he reveals himself to Lou. You'd be better off with some combination of a flashback reminder of the original whisper scene, and by putting Lou in the room when it happens.
PS On page 61 Lou talks to himself again. I don't think that's working here.
I know there's a lot of recommendations to change something or other in your script. Don't take it the wrong way. I love the story and the characters and the humor.