You can set the User Groups and the Undo Time Limit in the Configuration . If you don't want to use any of them, leave the first one empty and put a "0" in the second one. See the picture right below.
Now everyone will be allowed to use the Page Tree Eraser but if they make a wrong page tree, which includes invisible or non editable pages, they won't be able to delete it and will need to call the administrator.
If you want everyone to delete with the Page Tree Eraser and you want to give your users the chance to delete their recently made page tree with one click when it for example contains a small mistake but also pages they are not to delete.
If you don't want every user to delete page trees, then you can set User Groups. The people which don't belong to the User Groups can only delete recently made page trees if there is an Undo Time Limit.