I think they're easily implementable.
1. in red: track name can be inserted in the MIDI editor toolbar. I can live without the MIDI item name. This is much more practical than a separate FILTER window.
2. In green: ghost notes CANNOT be edited. Clicking on the track name in the toolbar is more logical. I'm tired of clicking by mistake on ghost notes that share the same space of notes of the current track!
3. and in blue: Do the piano keys need be that long? The fact that they're black and white already makes it clear. It'll provide more space for the MIDI take view.