Can I use the broken rule mechanism in the form to validate my own controls? Is there a way that I can check a bunch of things as a sort of validation then have it all pop up like you do when there are broken rules...

Yes, it does help to be efficient, but sometimes, in some cases, like this one, you have to do things by hand, and adding extraneous broken rules to a business object might cause other issues but if you have a reference to the form, you can do just about anything   You can always add your own error provider as well... it's just a component listed in the "All Windows Forms" toolbox tab.