I am traveling from Seattle to Italy, my first point of entry is Paris, with a connecting flight 1 hour 20 minutes later to Italy. What passport control etc will I need to go through at the Paris airport? I assume my luggage checked in Seattle will be checked direct through to my destination in Italy and I will go through formal customs there?
Yes, you will go through immigration (passport control) in Paris, and customs in Italy. Customs is a walk-through (just go through the "Green Channel - Nothing To Declare" lane).
For us, we arrived in Frankfurt and went through Immigration there. No problems. From there, we walked to the domestic flight area and flew to Florence. No Immigration there. We were quite surprised that we picked up our luggage and walked outside without being checked. If your connecting flight is a domestic flight within the EU, you may not have to go through Immigration again.
And if your luggage is checked through to the connecting flight, which it should be, it is unlikely that there will even be customs when you arrive in Italy.
You asked "What" passport control you will have to go to: in this regard you will only have one option. So just follow the signs for connecting flights and you will end up going through the proper passport control. Your bags will go to your final destination. In Italy you will not have to go through any sort of passport control again, since you already did so in France and you will have been on a "Within the EU" flight to get to Italy. Enjoy your trip!