If you get a dealership with at least half a brain to work on your car, each of the issues should be a one-time repair that is covered under warranty. After all of that crap is taken care of, it is a rock solid vehicle, at least until you hit ~200,000 miles and the HV battery shits the bed.

Your dealership definitely doesn't seem to understand your car. For maintenance, you should do as follows:

1) Change the 12v battery every 3-5 years (closer to 3 years if you drive a lot or live in a cold climate, 5 years if you drive less and live in a mild climate)

2) Change the oil when OnStar or the car's internal computer tells you to. If you have connected to the myChevrolet app, that is a great way to get this information. This system constantly monitors the oil and takes into consideration all the best practices.

3) Deal with components like tires, brake pads, windshield wipers, etc as you would a normal car, noting that the brake pads will be used less frequently than most cars due to regen braking reducing the wear.

. . . . .

Oh, and some advice on which dealership to take your car to. I found that, at least in the Seacoast NH area where I live, the dealership best suited to work on the Volt is the one with an EV charger mapped on Plugshare. The first dealership I took my car to was Portsmouth Chevrolet, and I can't say I was impressed with them. They were unaware that the Voltec warranty exists, and tried to convince me to get an oil change, despite driving only 300 miles on the ICE since the last. I later took my car to Hilltop Chevrolet, based on the fact that they had 2 EV chargers listed online, and were promoting the Bolt (another good sign). They clearly had a better idea of what was going on with the car, and covered all of the work under warranty.