After all the good information, let me try to give a direct recommendation.
Use the autopilot on divided, limited-access highways/freeways.
Use the autopilot on wide, undivided highways, marked with a center dividing line. Disable it when you see anything that could pose a risk, like tight curves, oncoming trucks or other cars that straddle the center line, potholes, unclear road edges, etc.
Do not use the autopilot in streets without lane markings.
Do not use the autopilot in streets where cars are parked partly or wholly in your lane, i.e. where there is no dividing line between you and parked cars.
Whenever you perceive even a slight potential risk while using the autopilot, grab the steering wheel firmly with both hands and be ready to overrule the autopilot either with the steering wheel or with the brake pedal.
If you spot a problematic situation ahead, disable the autopilot by pushing the gear lever up.
Note that the brake pedal disables the autopilot instantly and completely, while the steering wheel leaves TACC (Traffic-Aware Cruise Control) active. Note also that in a curve disabling the autopilot means that the force required to stay in the curve is switched off with the autopilot and has to be provided by your hands instantly. In other words, if you switch off the autopilot in a curve, the car will instantly tend to go straight, rather than follow the curve, and you will have to counteract that.