The first line of the last message should have said 'in addition to' instead of 'rather than', In the following expanded table, Key is the number of pseudoevents with configurable and fixed key bindings.  Gen is the number of General pseudoevents. (Current, from config-main.def.)

File          Menu                            Key  Gen
------------  ------------------------------  ---  ---
autocomplete  Edit - Show Completions         1,2   1 
autoexpand    Edit - Expand Word              1,-   -
calltips      Edit - Show call tip            1,2   -
parenmatch    Edit - Show surrounding parens  1,1   3
paragraph     Format - Format Paragraph       1,-   1
rstrip        Format - Strip trailing white-  -,-   -
runscript     Run - Check Module              2,0   -
runscript     Run - Run Module                same file
codecontext   Options - Code Context          -,-   2
zoomheight    Window - Zoom Height            1,-   -

My initial experiment with adding a fake event and binding in the user config-keys.cfg does not affect existing versions.  It appears to be completely ignored and does not appear on the list of configurable keys in the dialog.