I thought they'd said that Heisenburg made accurate data transmission via entanglement impossible. Has something changed in the theory?
One would think so. That's the way it has been going in science, something new is observed and next thing you know there are papers and conferences and a new symbol appears in the equations. Quantum entanglement is sure interesting, but it is hard to work with and there aren't a lot of observations yet. It may turn out to be very valuable and make all kinds of sci-fi things possible.
I don't know enough about the current state of the research and the physics underlying it to comment intelligently on those questions (causality & the uncertainty principle) as they're relevant here. But they are very good questions!