Number 2 , yes transducer and the noise and running for a couple of minutes is normal.

0-60 mph is just over 8 seconds so the turbo is not being allowed to play by the ecu.
Check lines on transducer as mentioned above,and the transducer is just below the airbox and access is bot to bad.

I have had issues with my 97 e300td going limp mode lately after refitting egr diode / resistor delete. Now there are no codes and it runs as normal after a restart but it has no turbo boost when it limps and to be fair my old w124 e300d was quicker off the line so I understand your wifes apprehension.