Keyboad Interface - CTOS like options instead of short cut keys

I loved the Convergent's CTOS (Burroughs BTOS). The last time I used it was about 20 years ago - I would have been in my early 40's. As Ishiguro's novels show, memories are a very strange phenomena!

Still, I think a user interface modelled on CTOS on Linux would be very desirable for people who have problems with mouse - which includes a very large population - the aging group. Unfortunately, this is also the group which can't scratch its own itch :(

The features I think would be very useful:

1. Extensive use of function keys. Short cut keys do not need to be fixed. There is no need for each operation to be uniquely mapped to a key combination. Operations available could be mapped to the function keys based on the state of a document/application. This is quite similar to the options which are often available on right click of a mouse. A panel could dynamically display the function keys with labels of operations which were available.

2. Mark and Bound. The Mark key was used to set up a marker. Cursor could be moved around. When the desired destination was reached, Bound key was pressed and the content between Mark and Bound was selected. This becomes equivalent to a 'pick'. An operation like move, copy and delete can be done on that. Move and copy would expect that the cursor to be in the target position. This becomes equivalent to a 'drop'. Since a standard keyboard will not have a 'Mark' and 'Bound' key, function keys could be assigned to that role as described above.

I wish I could remember the number of times my father called in Goa regarding missing documents. He would press ctrl-A instead of shift-A and continue typing. By the time he would phone me, he had made closed and reopened the document and I could not help him over the phone.

He would have spent hours painstakingly typing a document and it would disappear. I never did figure out how to get rid of ctrl-A on Windows98.