Tbh that's a little complicated for me Although what I wrote mostly follows that basic pattern except the outro is what the bridge would be and then everything after the bridge is skipped. That larger format would be more useful for a song about Kao-chan's story I think
I honestly have no idea, I wasn't thinking about the musical part at all. I don't play any instruments (and I don't know how to use computer instruments) so it probably depends on what other people know how to use
Hmm, I doubt anyone here knows how to play those instruments, but maybe something like Garage Band has digital sounds of them. Speaking of such instruments, have you ever listened to Wagakki Band? They're my favorite band. Actually Yuko Suzuhana is the main singer of Wagakki Band, but カンパニュラ is solo music of hers.
I think your lyrics ideas are already very good. I’m sure we can use some parts of it. But I would change it a bit to make it sound as good as possible. I made a list once what we can include in the lyrics. It’s somewhere in the beginning of this thread.
Although what I wrote mostly follows that basic pattern except the outro is what the bridge would be and then everything after the bridge is skipped. That larger format would be more useful for a song about Kao-chan's story I think 
I think what I was thinking of with that part was the Yuko Suzuhana song カンパニュラ. Probably depends on what the tune would sound like though
But I would change it a bit to make it sound as good as possible. I made a list once what we can include in the lyrics. It’s somewhere in the beginning of this thread.