Can the Edit/Merge layer button be disabled or shifted to a different position?
I occasionally select it instead of the Edit/Merge selection button and would like to disable or shift it to the bottom of the Edit toolbar.
Would it work to switch your keyboard shortcuts so that control+m merges selection (and then use that instead of the menu)?
I am a mouse clicky type instead of a shortcut user so keyboard shortcuts likely not a preferred solution for me.
I expect the Edit menu is not readily able to be changed.
Another option would be to add the Merge selection option to the toolbar and get into the habit of using from there.