Back in my film school days, a common phrase drilled into our heads by our professors was "Kill your babies". Nowadays I hear the same basic sentiment, somewhat sanitized to "Kill your darlings"." The essential idea is the same, though: sometimes you have a wonderful idea that just isn't working, and you have to be willing to give up on it.
It's a good idea in practice-- rather than kill yourself over something you love but can't make work, you drop it and move on. This is especially true in terms of scenes or single bits of dialogue, like the kind that gives you a "Hell, yes!" moment... but including them stops the story dead. Trim the fat, and move on.
However, sometimes it's more about figuring out what isn't working about it, and fixing it. Get rid of the bad, but keep the stuff you love.
This is a roundabout way to say that I figured out a problem I had been having with Way of the Shield, namely that the main character didn't want anything. He was essentially being a hero because that's the kind of guy he is, but there's got to be more to it than that. (This is one of the criticism that was laid on the Captain America movie-- he wants to go fight in WWII, but his body is stopping him. At the end of Act I that's fixed, and he doesn't have any more character arc.) Dayne had a plot arc, but no character arc.
Here's the thing, though: I kind of knew the solution, but didn't accept it until just this weekend. Now that I have, I can feel the rest of the story unfolding in my head. Now, I think it's going to work.