How can I force Safari to perform a full page reload, without using the mouse?

Solution 1:

Enable the Develop menu from Safari menu - Preferences - Advanced.

On Safari version 11.1 and above :

CMD+OPTION+R reloads the page ignoring cache.

On Safari version 9 and above :

CMD+SHIFT+R reloads the page ignoring cache.

Emptying caches seems not to reload the stylesheets everytimes…

On Safari below version 9 :

Empty cache and then reload so full "hot key" would be :

CMD+OPTION+E

Then

CMD+R to refresh the page

Of course probably turning opening and closing a New Private Windowfrom the File would also work but…

Solution 2:

The shortcut has now changed to OPTION + CMD + R. (Safari 11.1)