Edits Finished, Doubts Setting In

I think today's blog title explains it all.
When do you know you've edited enough to improve your manuscript?
Right now, I think I'm simply moving the words around and making more of a mess than I had when I started. The one saving grace is that this is a three page manuscript and not my 400 page TNR fantasy. Come to think of it, I know I could easily cut 20K from the fantasy, but a 500 word story is tough!
After I deconstructed a few picture book/easy reader stories (typed into computer, printed and sliced and diced), I thought I was ready to tackle the editor's comments. Most of them are easy fixes: resolution comes to quickly, the fly character is acting too human, etc. See? Easy to fix.
But then comes the biggie: Story structure/pacing
Talk about having me bumfuzzled. In a 90-100K romance novel you have some wiggle room. Usually you have some sexual tension to build to the first kiss, which could be anywhere from the first few pages to the middle of the book.
Children's books have to follow strict guideline. There aren't 100 pages to muck about in building the tension, you have roughly 30 pages, or 500 words from intro of characters to build conflict to the climax and then resolution.
I think I managed it. But how do I really know? Yes, I could start mass querying, but I'd rather go into that will my guns loaded and blazing away. I HAVE to be ahead of the other 99% of the people in the slush pile.
Rejections don't scare me, trust me, I have enough from my romances to paper a wall. You learn to ignore most of them and move on.
Rejections without a reason scare me. I can't fix what I don't know is wrong. And yes, some of it will simply be subjective opinion--that's the nature of the biz. But again, I'd rather have as perfect of a manuscript as possible because I have seven other related stories I'd like to sell as a series.
I have to admit that I'm far more passionate about my Peter stories than I ever was with my romances. I'm hoping that passion shines through.
Write on!