How can I set a keyboard shortcut that includes the backspace key?
To change the shortcut of a service, run plutil -convert xml1 ~/Library/Preferences/pbs.plist, open the plist, and change for example

&lt;key&gt;(null) - Some Service - runWorkflowAsService&lt;/key&gt;
&lt;dict&gt;
    &lt;key&gt;key_equivalent&lt;/key&gt;
    &lt;string&gt;@~a&lt;/string&gt;
&lt;/dict&gt;


to

&lt;key&gt;(null) - Some Service - runWorkflowAsService&lt;/key&gt;
&lt;dict&gt;
    &lt;key&gt;key_equivalent&lt;/key&gt;
    &lt;string&gt;@~&amp;#x8;&lt;/string&gt;
&lt;/dict&gt;


Then restart to apply the changes.

@ is command, ~ is option, and &amp;#x8; is delete (Windows backspace). Forward delete (Windows delete) would be &amp;#x7f;. The shortcut strings use the same format as in DefaultKeyBinding.dict.

To change a global shortcut set in the App Shortcuts section, run plutil -convert xml1 ~/Library/Preferences/.GlobalPreferences.plist, open the plist, and change for example

&lt;key&gt;Some Menu Name&lt;/key&gt;
&lt;string&gt;~@a&lt;/string&gt;


to

&lt;key&gt;Some Menu Name&lt;/key&gt;
&lt;string&gt;~@&amp;#x8;&lt;/string&gt;


Then quit and reopen applications to apply the changes.

Application-specific shortcuts are stored in ~/Library/Preferences/*.plist and ~/Library/Containers/*/Data/Library/Preferences/*.plist.