Is there a way to identify unmapped keys?

[Shalmaneser]

Is there a way to identify unmapped keys?

[soapybirds]

One of these plugins should help:

Bound​ Keys
packagecontrol.io/packages/BoundKeys
“A Sublime Text 2/3 plugin to list the contents of keymap files and indicate any clashes/overrides.”

Find Key Conflicts
packagecontrol.io/packages/FindKeyConflicts
“Plugin for Sublime Text to help identify conflicting key mappings.”

Or you can search manually through your *.sublime-keymap files.