Protractor gives you access to the console log while it is testing. This functionality could be used to verify that no errors are occurring, or other similar things you might want to test.
That "flash of ugly handlebars"... can that be avoided with ng-cloak? Just curious since I recently ran into (and solved) with that method.
Yes, or use ng-bind="expression" in an element.
There's in fact a built-in plugin called "console" that does exactly that.