I am using Menu with a localized label/text.

Currently I do it this way:

Menu menu = new Menu(null);
menu.textProperty().bind(someProperty());

I do it similarly with MenuItem:

MenuItem menuItem = new MenuItem();
menuItem.textProperty().bind(someOtherProperty());

The need for a String in Menu's constructor is a little bit annoying here.

I suggest you provide a default constructor with no parameters. (as you did with MenuItem, too)