This


Oiled cotton gauze filters don't filter as well as paper.

K and n filters are junk we don't run them in the race cars and not in the prerunner And those see tons of dirt and dust


Just a regular paper filter is fine

I've heard a lot of rumors of the oil in the k&n filters ruining maf sensors. Really not worth the risk imo. They flow a little better, but it's at the expense of lesser filtration. And it's not a noticeable gain.
Fram or Stp paper filters would be fine.

Stock? Just any regular one from the auto store is fine.

As long as you change them out under recommendations. I say annually.