Jim, just an idea; would it be possible to add a second column of checkboxes on the right, with a 'Lock' column checkbox in the column header? It could communicate the idea well, as well as allowing you to only unlock the layers you need.
Alternately, just add a checkbox to the button and change the text to 'Disable(/Lock) Scene Editing'. Or make it a checkbox as well.
...actually, that's kind of pointless. If you're going to edit the scene, you aren't going to want to mess with unticking a box for the one thing you want to edit anyway, and the extra checkboxes would just add clutter to the layout. Hmm. There HAS to be a better way! (Maybe just a checkbox under the preview pane with 'Lock Scene Editing', checked by default?)