Using Tropes to Fix a Weak Plot

I am heavily plotting Post-Apocalyptic Ninjas (with Mechs!) in a vain effort to forget that, right now, agents are judging my soul. It's taking a lot longer than I think it should (the plotting, not the soul-judging), partly because my wife and I decided nine kids wasn't enough, and partly because Post-Apoc Ninjas is the novel I have to love more than the one I'm querying,* so I want the plot to be STRONG before I start writing.



And I've discovered a couple things: (1) my first idea is often...