Congratulations on your new ARSandbox.
AFAIK, there is not a list of short-cut keys because you can assign just about any key to any function. You did this tool binding during the installation when you used the “Extract Planes” tool. To find the available tools, explore the SARndbox menus that popup when you press a key.
To create a stable set of hotkeys, see Step 15 of the Instalation instructions. The example WaterTool binds “1” to global rain and “2” to global drain.