[ratsttam]

ANY faulty sensor will wreak havoc on these cars (and most other electronically controlled cars for that matter).
The engine running rough (either high or low rpm) can be the result of a lot of variables. Different sensors, or physical problems such as bad plugs, wires, or coil packs.
If moving it from D to 3 helps, than you're just putting a band-aid over the problem. Sometimes going to a lower gear will allow the engine to run "smoother" at a higher rpm than rougher at a lower rpm if it's not firing right.
Also the strats have power assisted brakes and steering. If you lose engine power, you can still stop the car and steer. It just becomes extremely difficult. This is NORMAL with any modern car with power steering or brake systems.

Change that crank sensor out and get back with us with any other codes that may come up after that.