Summary: Why not tu use the existing ruler form the MIDI editor for the continuous notation view.
1)
Make ruler visible - all the time, not just on hover
2)
Make ruler larger - currently with the working zoom level, the ruler is far too thin.
3)
Lock the ruler to the top and remove ruler in between staves - it is locked to the top in the arrange and in the midi editor. Also, the in-between-staves rulers are literally 2-3 pixels tall with working zoom level, so unusable and even disruptive.
The very top of the notation window is unused so why not to use it for the ruler like it is in the arrange and midi editor.
4)
Do not change the size of regions and markers with zooming. - at small zoom levels when the notes are still easily readable, markers, regions and bar numbers become unreadably small.
5)
Place markers above the time - like it is in the arrange and midi editor