So today I heard from my cousin who had graciously accepted the task of being a beta-reader. I didn't get much in the way of "here's what you did wrong and need to fix," and the letter was little more than a "I loved it" blurb, which is hard to trust from family, but she said one thing which stood out. She told me about a reaction she had to the emotional climax of my story. Her reaction, when she read it, was to shut the book and storm off, unable to continue until she had calmed down.
I count this a huge victory. The fact that she reacted so emotionally meant that I created characters worth reacting to. Everything else is fixable....getting that part right solidifies my decision to do this thing. Write on.