Books often change quite a lot as you're writing them and the book you've written may require a somewhat different protagonist than was called for in your original outline.
Over time, as you write more, you will learn to recognize which ideas can be developed easily, which can be developed painstakingly, and which can't be developed. And you will learn more about your own process of development, which will help make both easy and difficult development go more smoothly.
Even if you didn't have a billion story ideas, I suspect you would still struggle with revisions. It's easy to think of the writing as taking you away from the revising, but don't get too caught up in that love triangle. The relationship between you and revising, between you and the work you've already created—work that you know needs more work—is what's at the heart of this.