Rotorhead34

I have ordered the ecu, it hasn't arrived yet. However, I've been doing a lot of reading on the install of these and they dont seem to very much difficult than other things I've done in the past. I would like to know what are some things to look out for. I want to remove the ecu completely, however, the a/c is staying, the power steering is staying. I have a CAS, 4 direct fire MSD 8702 coils, o2, TPS, air temp, and coolant temp sensors. I have an electric fan on its own thermostat, could I operate the fan with the ecu? Could I control boost with it? Will it need an AIC to run the a/c? Are there any reasons to leave the part of the ecu wiring harness in the car. What about cruise, that is staying in as well. Thanks.