As someone who picked up songwriting a few years back after having been a serious musician in my younger years, this is the kind of applications I love to see.

This is exactly how it should be. You found the right pain points. Now extend it with piano and you are getting really close to something I would pay for.

There are some small things like the use of the word "tabs" instead of chord charts but I love where this is heading.

I might write my next song in this. Or even try to add my older songs.