I’ve been using Blender for few months.
I really found more productive swapping Left Right Buttons. (30 years using computers) So I did
Other thing I did change and stop being annoyed, is Alt+RMB to place 3D cursor
Other, in Edit Mode, RMB to display menu to change selection from Vertex, Edge, Face.
But this last one, it seem to be even yet not practical, too many clicks to do a simple selection.
Using the icons in the lower bar for that is not practical either, it is distractive, you can blind type the keyboard, not select buttons with the mouse.
So I see is not used (Edit Mode) Shift+Ctrl LMB
So I want to use it to change to Edge select being in Vertex select mode. Not permanently just if I Shift+Ctl LMB in an edge it be selected.
I do not see an option for that in the User Preferences/Input
So I thought may be a script could do that or a hack in the key map file.
In fact the options I do use are not in the Input Options, I did add them in the key map file.