On the subject of song navigation: A song navigation bar, with which you can move the current view frame horizontally and vertically (depending on the current zoom level) with a click on a position on this navigation bar. Also you could move the frame in the navigation bar and its position is transferred directly into the main window.
This helps to ensure that you always have a good overview of the song and is always able to quickly and easily reach any position.
* (and then you can jump either the Playhead with a shortcut in the middle of the picture or to the Playhead, but this scrolling is independent of the Playhead)
In addition to shortcuts for zoom, there could also be shortcuts for controlled scrolling * This would benefit the MIDI / audio event dragging, where scrolling is currently only possible when dragged over the edge. So you can move quickly & directly to another position and gets in addition to the zoom options & song markers another way of song navigation.