It would be useful to have a list of all programmes, select one, click buttons (or R-click) for choices of Allow - Ask - Block; the ability to select several and Delete is handy . Also good if these lists stayed put, instead of returning to top.
'Useability', i.e. convenience for the user, is v. important. Several of the apps. that I've chosen to use are 'Useble' - more important than bells and whistles everywhere!