Undo
-Z
Redo
Shift- -Z
Cut
-X
Copy
-C
Paste
-V
Delete
Select all
-A
Split region at Playhead
-T
Join selected ( regions )
-J
Snap to grid (on/off)
-G
Show/hide track mixer
-R
Show/hide Track Editor
-E
Show/hide loop browser
-L
Master volume up/down
-up arrow, -down arrow