Is there a place in the documentation that concisely displays all/many of the keyboard shortcuts? Or does anyone have a nice cheat sheet?
Cubase manual page 546. Now that wasn’t hard.
This is sheet of factory shortcuts, of course. You can set your own shortcuts, of course.
Or do you know this?
lol thx. 
Actually I knew that was there, I was just testing you.
I was looking for a shortcut that would quantize just the lengths of MIDI notes. I know (Q) for quantizing the beginning of the notes, but is there shortcut to quantize the ends (lengths) of the notes?
Yes, there is. Do you test us again? 
In the Key Commands, open the Quantize Category folder, and find Quantize MIDI Event Ends, or Quantize MIDI Event Lengths. You can choose, which one do you want. These function are little bit different each other.
Thank you very much.
I never had any plans to change the key commands, so I never thought to look there, but now I know it lists every command and is searchable too. I had searched the Operating Manual for MIDI ends and lengths but didn’t find any shortcuts mentioned that were useful. Also, it is MIDI event ends that I wanted; I didn’t realize they had a separate command for each the event end and the event length. I appreciate the help. So much easier than adjusting the ends of each note by hand… which is what I was doing, sadly.
Yikes, that costs 10 times what the keyboard I’m using costs. Time for some white spray-paint and a Sharpie.