As I am testing things with MV, I decided I wanted to clean up my mess and realized the "Clear all cells" option is gone. Not there in X3 either. How does one clear all cells now? (I truly hope this is not a "One by one" answer). It used to be accessed by right clicking the panic button.

Then out of curiosity I opened the same project in each X edition back to X1, and things are disappearing from MV as it "evolves."

You know what, Michael? I recently wondered exactly the same thing (I only use the view occasionally). But since you mentioned "It used to be accessed by right clicking the panic button," I just thought I should click-hold the panic button.......and it's there. 

Excellent, thank you! "Long press" would never have even crossed my mind (but the visual indicator is on the button that there is a context menu "somewhere.")

yea, that is pretty obscure.  I'm a inveterate button pusher, but it would have been a while before I hit on that.
 
@