There’s not a master list of keyboard shortcuts. During the beta period there could be some changes, e.g., pb2 introduced a different shortcut to toggle the left slide-out.
You can view the keyboard shortcut assignments in the menu bar and submenus of the DEVONthink application.
There’s (somewhat limited) ability to change/assign keyboard shortcuts using System Preferences > Keyboard & Mouse - Keyboard Shortcuts. If you mess up, there’s a Restore Defaults button.