Plastic cowling removal on 2013 4 runner?

I'm new to this 4 runner thing. Just bought a 2013 with 100K miles on it. I go to the desert a lot and felt I needed a 4x4. I was wondering if the plastic cowling pieces are really needed on the skid plate. They appear to channel air through a couple of screens to cool something I guess? Those plastic doo-hickeys are a pain to remove and I'm just wondering if those two plastic pieces are really needed. I tried to find something under search but nothing came up.

Also, are the 4 skid plate bolts 8mm x 1.25 pitch x 1" long. That's what I measured when I checked them.

I replaced them with Stainless steel ones adding washer and lock washer. They were a bit of a pain to put in (kinda tight) which surprised me. I thought they would be loose if anything! One was already stripped out and I may have to tap to 10mm. did put a little anti-sieze on the new bolts.

Appreciate any feedback,
Thank you!!