Is it possible to have a caesura mark only on the treble clef staff… I can’t find a way to suppress the lower one from also appearing by way of settings.
1a)… and for that matter, I also can’t find a way to select just one of them so that I can hide it.
Regrading the beam orientation on the first set of cross staff notes (w/ the blue note heads). . . This beaming seems upside down. Is their a way to flip it so that the 16th beam hangs below that of the 8th beam?
You can’t flip that secondary beam to the opposite side of the beam line, as that would create a beam corner.
Caesura marks affect all staves at the moment, and they can’t be hidden individually (they are a single object). You may find it acceptable to put in a fake caesura with a text item (Shift+X, set the font to Bravura, copy and paste one of the characters from this page).