Pure energy only = no time. ?
Okay, that I might concede, L.

The "Big Crunch": do you reckon that everything, every last little particle of anything, will be---what? Swallowed
by black holes? Turned into what is labeled as dark matter, but which may not be matter as we know it at all?

Your word 'crunch' to me implies some kind of impact/implosion--though to sure it could be followed by an explosion. I'd always entertained the notion that eventually most of the spacial bodies will explode,
without necessarily having had a collision.