TPMS INITIALLIZE?

I don't know about the first question.

But for the 2nd question, if you buy the set, you should have the dealer set up your TPMS using their techstream. The TPMS have serial number on them, so they will be using those number and input it into the TPMS system memory in the vehicle. Your original TPMS serial is gone and will be replaced by the 2nd set you bought. I hope that helps? lol...

 

Your TPMS system was initialized at the factory or the dealership. You do not have to do anything.

If you have not had a leak in a tire and low tire pressure then you would not have seen the TPMS warning light. I do not remember ever seeing the TPMS light when I start the car. I had a screw in one of my tires that resulted in a slow leak and a TPMS warning light. It worked just fine.

There is a TPMS button next to the OBDII connector, about where your right knee rests. Pushing this button resests the pressure setpoint for the TPMS system. If the tire pressure falls about 25% below this setpoint then you get a warning light.

NutzAboutBolts answered your question about the second set of tires.

 

There's a TPMS sensor that can be programed to match your original TPMS code so you can swap wheels without reprogramming the ECU. No experience with them, but it seems the way to go.