I will echo the advice I gave when you asked about
getting a proofreader which has come to pass.
... Let's imagine worst case. You hire a script reviewer for a couple hundred dollars to give you expert feedback on your script. S/He tells you that your character development is poor, the story line is muddy, the premise and action is unbelievable to this point and the pacing is off. In addition, there are numerous spelling, grammar and formatting issues. What is your response going to be? ...
How the process works varies by reviewer. As a reader, the first 10-15 pages tell me tons about the script. If a writer can't sell me the story, characters and use good formatting in that interval, the rest of the script often doesn't get any better and it's a pass. If a writer sells me there, I'll read the whole draft. From that point, I can often give more specific notes. As a reviewer, I'm paid to be bored out of my skull. I try to be gentle, but let's face it bad is bad. Writing is part art and part craft. The craft side can be tweaked. The art side is more or less innate. I believe it can be developed over time, but most new writers want to be superb instantly, hence the success of Blake Snyder's beat sheets (the screenwriting equivalent of Bob Ross' art techniques).
After reading a couple hundred scripts, it's easy to distinguish technique from talent. New writers complain "... but look at X written by Y. It does the same thing." Fine. You aren't Y and you didn't write X. Chances are, X isn't what Y wrote but a doctored version. Nonetheless, my point is that as a writer receiving feedback, you can either respond defensively or stepping back, think about it and apply it. Nobody says a writer can't have several variations of the original idea. Each time a writer comes at it, s/he is learning more about the story, the characters and the craft.
Just maybe you should accept that parts of your script don't work. It doesn't mean YOUR script is unsaveable or unuseable. But it may be helpful and instructive to see how the hired writers would approach your same issues and resolve them. It may give you insight how you can better work with your script. When I've had my scripts reviewed and revised by experienced writers, I've learned a lot. As director you will continue to have large control over what the final script will be. I can only urge you to not allow yourself to be too tied to it. As a producer, you will find that even in production, budget and other situations will arise that can require "plan B" tactics. Having these alternatives can be an asset.
Do you think I should hire this particular consultant or should I keep looking? My instincts say to keep looking since she seems to want to change the whole in order to make it work, where as others may be able to pin point more specifics as to what can be improved.
In the end, it's not about her (or other consultants)--it's about you. I'm not clear on the distinction between "making it work" and "improved". Isn't the purpose of "improving it" to "make it work"? At some point, you may need to tell your gut to stop looking at the trees and step back to look at the forest.
I know writers who write themselves into a boxed cell and keep digging down. Often it arises because they have that one clever element they want to play out but at the sacrifice of the plot and arc. I remind them that the box is fictional and arbitrary. Sometimes you need to go back a few steps and make a different choice. They don't like to hear "cut it out" but in the end, it frees them up. And often later, a new circumstance arises that lets the situation play out albeit a different context. You seem to bang your head a lot on this script based on your thread postings. It strongly suggests to me that a new course of action is needed. Maybe a new approach to your story may inspire you.
No one here has read your script. Until recently, you mentioned you didn't have a completed draft. None of us can comment whether she is right or wrong, or even make wild guesses about the quality of your script. Maybe it needs to be totally overhauled. If you ask her to try to remain faithful, she may be able to pinpoint specifics since she's read the script and can provide alternatives.
I also merged characters and locations in my previous drafts, but am always up for more if a consultant can make it work. Is it worth merging characters if it leads to coincidences in the story?
Again, no one here has read your script. That's a pointless question. The answer is yes. The answer is no. The answer is maybe. The issue could be debated endlessly. Could anything be more vague than "leading to coincidences"? To answer that question, we'd have to read your script to learn the specifics for ourselves. Your sharing would be rather pointless since it must be understood in the whole context of the movie, not just a few "Well X did this but now Y is doing it, so I'm wondering ...". Not helpful. There are unstated dependencies. We need to know everything about X and Y in the story, not just that short statement. You know and have lived the full story, we haven't.
As Maz and many others have suggested, post your script. While I can understand if you're reluctant, if you choose not to post, then you will need to work with her or another consultant who has read the whole script to answer that question and others. Given your prior posts, I think it would be a good thing to work one-on-one with someone to help resolve all the head-bangers. From your posts it does sound like a rather Rube Goldberg plot--planting DNA, with cops and crooks playing both sides, people blackmailed to not do their jobs, gang standoffs through false leaks, etc. You seem to have a penchant for building boxes.
You wrestle with details where the first question should be "What's your underlying story?". If I understand it, "a good man runs afoul of crime lord who destroys his life, transforming him into a criminal". Pick one or two of those plot elements that you want to keep and give the consultant some flexibility to weave those into the script to tell your underlying story. It's possible to mix old and new.
Having a local co-writer may be an alternative. Maybe one of the filmmaking collaborators who was positive about the script can work with you. Everyone here has their own projects and finds time to help each other with scripts. If some of your filmmaking collaborators will be helping you shoot, ask if they would be willing to provide some time as well. They probably have a better idea of what resources you'll have as well. Good Luck.
