Song 7 was a dud, sorry to say. The melody just wasn't memorable enough. The chords were ok, and might be salvageable for something else. It didn't work to set a pre-existing lyric to music, as I attempted to do.
The key was Eb, and I started in F, then Abmin, Bb7, Eb, Gmin, Fmin, E7, and Eb. So II, IV, V, I, II, V (with tritone substitution), then back to I.
I would have been happy if this were my first song, but it is not even as good as that one. The last two are the best I have written, so it will be hard match those.
Working in a different key gives me different ideas. I've learned that certain notes have certain character even in different keys, so a D will still be D no matter what. F#maj 7 sounds tangier to me than Cmaj7.
As I work, I train everything at once. So my ear, the facility of my fingers on the keyboard, the connection between my ear and my fingers, my knowledge of music theory, my compositional mind as a whole, etc... are all engaged at the same time. The parts that lag behind, like my keyboard skills, have to catch up with the parts that are more advanced, like my feeling for form and structure. I feel confident enough to say that I can reject a melody that is not memorable enough, rather than having to take what I get.