Is there a way to prevent the menu of an app (e.g. gedit) from hiding when it loses focus? I would prefer that it stay visible all the time. Thanks.
No currently supported way. You could stop it from running or trick it to run menus inside the apps, but both are rather hackish.
My best advise is get used to pressing alt. Your "not supposed" to access menus with the mouse anymore, just press alt and say what you want it to do.
For example press alt and type save. However I find that personally very cumbersome for menu items I don't already know about.