Pjmoody

I bought a 2002 996 Convertible that was flood damaged. I changed the oil, I cleaned the cylinders by flushing the cylinders out one at a time , 2 had contamination in the cylinder. Now I'm wondering if the valves that are closed have contamination on the head side ?
Contamination consisted of silt, pink fluid and water.
I purchased a used immobilizer, key fab and ECU from the same car. When I install these do I need the dealer to do anything ?
Can I turn the car on with out the seat memory control unit ?