Unrealistic Expectations? Unrealistic Expectations, Party of Four?

I am a working writer (film) and director.
I have written a children's book. People seem to really like it, 

"People"?  You mean like your neighbors and friends and plumber and stuff?  They don't know anything about children's books.

and of course I want a good illustrator and want it published.
I was thinking of getting an pro illustrator myself and presenting it to editors in it's completed form--is this crazy? 

Yes.

I imagine editors want to be part of that process, but also fear a hack artist getting assigned to it.

Well, get a good editor.

Also, isn't writing children's books like opening a restaurant--something that everyone wants to do but almost nobody really succeeds at?

No, no.  It's worse than that.

Writing children's books is like singing-- something EVERYONE, even the ones who don't know how to cook, think they can do acceptably.  I swear to god, if you started stopping people on the street and asking them if they had an idea for a children's book, 99% of them would say yes.  This is why editors don't generally admit to what they do when speaking to strangers.

For restaurants, there are three categories: people playing with the idea of opening a restaurant, people trying to run a restaurant, and people running a successful restaurant.

For children's books, there are four categories: people playing with the idea of writing a children's book, people trying to get a children's book published, people who have gotten a children's book published, and people publishing successful children's books.  As much failure as there is in restaurants, there is much, much more in books.

However: there are many things you can do to lessen your chances of failure, and among them are writing a great deal, reading a lot of children's books, and finding out as much as you can about the business. 

I mean, who is more likely to run a successful restaurant-- the person who has pipe dreams of serving his grandmother's recipes to other people, or the person who has practiced running a restaurant, investigated how other restaurants are run, and educated themselves about the business of running a restaurant?