Can I resize the midi editor window to specific dimensions and save that as a default?
yes, the MIDI editor position and size is save and restored on clip basis.
Currently, i can only close the midi editor window with multiple shortcuts, by opening the File menu window (Alt+F), then choosing Close (Alt+C). Is there an option that would allow me to toggle opening and closing the window with the same shortcut?
none, sorry. there's no shortcut to toggle open/close a clip editor and Esc won't ever close anything besides a modal dialog (a MIDI clip editor is not a dialog, it's a full blown top level window; however, you may close it the usual global keyboard shortcut from your DE/WM in charge, eg. Alt+F4 here's on KDE/Plasma).
In the midi editor, I can't find actions for navigating from note to note. Do they exist, and if so, what's the syntax?
navigate or "step selecting" notes? there are indeed these Transport/Step/Note/Backward and Forward on the later case.
A similar question for clips in the main window. Are there actions for navigating from clip to clip, not only in the same track, but across tracks? (up and down)
none. you can only navigate (highligth) up and down by track (not clips): main menu Track/Navigate/First, Previous, Next, Last and None.
yes, the MIDI editor position and size is save and restored on clip basis.
none, sorry. there's no shortcut to toggle open/close a clip editor and Esc won't ever close anything besides a modal dialog (a MIDI clip editor is not a dialog, it's a full blown top level window; however, you may close it the usual global keyboard shortcut from your DE/WM in charge, eg. Alt+F4 here's on KDE/Plasma).
navigate or "step selecting" notes? there are indeed these Transport/Step/Note/Backward and Forward on the later case.
none. you can only navigate (highligth) up and down by track (not clips): main menu Track/Navigate/First, Previous, Next, Last and None.
hth.