1. A "trusted" computer does not mean a computer that is trustworthy. The DoD's definition of a trusted system is one that can break your security policy; i.e., a system that you are forced to trust because you have no choice. Pd will have trusted features; the jury is still out as to whether or not they are trustworthy.
3. Like everything else Microsoft produces, Pd will have security holes large enough to drive a truck through. Lots of them. And the ones that are in hardware will be much harder to fix. Be sure to separate the Microsoft PR hype about the promise of Pd from the actual reality of Pd 1.0.