Dual monitors and Compose

Scrivener Scrivener for macOS
1

I am using a dual-monitor setup and would like to put the binder on my secondary while working in Compose mode on primary monitor.
I found this in the manual:
“When using two monitors, you can configure Scrivener to use the secondary display as the composition window instead of the primary display. This can be adjusted in preferences.”

My questions:

  1. Is it possible to put Compose on #1 and binder on #2?
  2. Strangely, now and then (!) Compose opens on monitor #1 and leaves #2 blank. How so?
  3. When I am switching spaces through keyboard shortcuts, or changing programs through Command-Tab, the Quick reference pane is mixed up with the Compose window, overlapping it, instead of staying in it’s space (and therefore, monitor). Very annoying when wanting to work fast. EDIT A workaround seems to be not to put the QuickReference in fullscreen/to make it smaller than the actual screen.

Sys specs: OS X ElCaptain, current update. 2 spaces, assigned to two monitors.
Thanks!