2001 cl600 theft recovery! i need help!

[seth70]

im new here, and i recently thought i got a good deal on a 01 cl600 with almost 100,000 miles on it. my delima is as follows. it didnt have a trans, and the main ecu/ecm was missing. i got a low milaege trans, and found i had to get a new ecu from mercedes, and i did. i was then told the ecu would have to be programmed at the dealer. i was a nissan tech for many years, so im pretty savy i think, and its was the same with them. however it has many things not working, the air suspension is all the way down, the windows roll up then back down slightly. i think this is just the bcm needing resetting, but i dont know how to do it. but the car will not turn over or do anything when i trty to start it. could the key need reprogramming? im not anywhere near a mercedes dealership, so im begging for help! thanks