export (String) var MemberType
If your scene inherit the script that contains
export (String) var MemberType, then yes this scene will have the option to change the value of this property inside the Inspector, too. (Just put the scene as a child node is not the same as extends its parent class, a script is also a class that extends the class of a node)
If you want a scene to be reused, save this scene. Later you can just load it and instance it, the options you exported will also be there.