Thank so far,
I do not know what you did, but some part is right now, some not > Blue edit button icon still missing
I think there must be some sripting interference, as main navigation does miss icons as well – see header right of menu-item Kontakt as when you bring the size of the browser smaller, the responsiveness does show an icon for navigation, which is missing as well….
Disable of right click is a feature of the plugin WP Security, only to find inside in configurations, I just switched it off.