If the window is sized and zoomed to be the same size or larger than the layout, the scroll bars will disappear. Otherwise, they will be present.
If you have FileMaker Advanced, you can set up a custom menu that does not include these mode changes and this will disable these features for the current layout. Scripts can selectively install such menus so that Full Access users still have access to the view options while others do not.
Settings in Manage Security can be used to keep users from entering layout mode.
Layout based Script Triggers that are tripped by mode changes can also short circuit mode changes that you do not want to permit.