Top 50 most common keyboard mappings in the default Softimage keymap.
After the obvious F1 (22 assignments) and Delete (17), the next most-assigned key is F5 with 15.
Wednesday word cloud: keyboard mappings
You can use the PageUp and PageDown keys to move back and forward through the history of recently inspected nodes.
If you right-click one of those arrows, you can see the history list of inspected nodes, and select a specific node to inspect:
If there’s no property page open at the moment, pressing PageUp (or PageDown) will open a property page and load the most recently inspected node.
Here’s a related TD Survival video on PageUp (and some other handy shortcut keys):