Filler cap recess is known to turn, as the folded lip catches moisture, any car not garaged in less than sunny climates is sort of waiting for that one. Other two, don't know is they're common or not, but would assume the PDC sensor to be simple to fix, pop the sensor out and take it to your local body shop.
As a note, no idea at all if this is common but I took my rear number plate off to change it over when the previous owner took his personal plate off, and it seems around the two circular plate mounts, I've got some considerable bubbling around these two mounts. No pic I'm afraid as it was raining and I needed to get the plate changed on that day, but perhaps one to be aware of. Most owners will probably never see behind that plate.
Rust is one of those things that's easier to treat sooner rather than later, so might be worth checking....
EDIT...Just seen RichardP's comment and I stand corrected on the appropriate points.