As to the ride height, either you have the wrong springs or the wrong spacers. I would verify the numbers for the springs. They have options based upon the variants of the base model your car is.
Once the springs are right the height can be varied by the thickness of the rubber spacer spring mounts.
As to the tranny, I would look to the engine speed and/or the mounting of the differential. The engine speed should be around 600rpms and should stay about the same after engagement.
Bosch Master, ASE Master, L1
33 years MB technician