The main concern though is keeping the user as the final arbiter of his own data. He wants to delete it? Bam! It should be gone. She wants to allow someone else to see it, that other entity should be allowed to see it. But that other entity should not be allowed to delete her data. Nor should it be allowed to let anyone else see that data.

The user being in control of access to his/her own data is not a concept that should frighten any legitimate business people. But businesses being in charge of access to a user's data is absolutely a concept that should frighten users. The power of determining access has to be shifted back to the user where it belongs. If some businesses that specialize in "data brokering" are harmed because users are suddenly able to choose to disallow them access, so be it.

Again, allowing businesses to influence and determine who gets to access a user's data is literally the reason we're in this predicament in the first place. Solve that stuff separately if you want, but under no circumstances can end runs around the user's ownership of their data be allowed.