Which key is the saddest?

Re #2, I'm not a programmer, but as a writer I find the same thing to be true. I work better with a pen and legal pad than a keyboard. I've got this feeling that we have neural pathways built for typing and, subconsciously, we favor phrases, words, and sentences that are easy to type. I know I even have a tic where if I pause to think I'll insert extraneous commas. It's kind of like how musicians tend to improvise around licks and scales that they have practiced a lot. There's something to thinking about the idea of a song on paper that is more creative than unintentionally falling back on chords/forms that are easy to play. (Adam Neely discusses this very well here: [this video] )