Seeing the recent activity here reminded me that I should probalby circle back, since I started this thread. My testing concluded and the end result was PhoneLeash v1.7. Of course, there were other testers as well. Even though my primary interest was the SMS forwarding part, I made an effort to test all the features. I have been using PhoneLeash daily now for almost a month, and it's THERE as far as I'm concerned.
As far as the whitelist/blacklist, I concur with the simplicity approach - make them mutually exclusive. Besides being easier to understand and set up for new users, I believe that method will keep the memory footprint down in size.
Help yourself while helping me: Sign up with Dropbox and we both get 250MB extra space. Thanx!