Question

I know I can do this by pressing Insert in INSERT mode, but that requires some stretching. Is there any more convenient shortcut to go directly from NORMAL mode to REPLACE mode?

Answer 1

From the ViM manual:

5. Replace mode                         *Replace* *Replace-mode* *mode-replace*

Enter Replace mode with the "R" command in normal mode.

Of course you can map any key to R, for example by doing

:map <F5> R