It seems to me that hiding the minimize button should result in the minimize functionality being disabled. To that end, how about naming the new WindowControl properties 'CanMinimize', 'CanMaximize', etc? That would be a little more clear; for example, setting 'CanMaximize' to 'false' suggests that double-clicking the title bar would not maximize or restore the window.
You should also have the CanMinimize property change handler coerce a new value for ResizeMode (if the base value of ResizeMode is set to 'CanMinimize', then it should coerce 'NoResize' instead).
Mike