AD firewall question

[8man]

I've started slicking up the firewall. Thought I'd do all the holes and then start over with new ones as needed, but

IMG_1937 by Robert Moorman, on Flickr

I have read that someone used the two holes on the riders side for AC hoses. I closed up one, but left the other one after I thought about what I had read. Should I close up the other hole?

Then on the driver's side, there are 4 holes at the top of the firewall, they are indented. Are these needed? I bought the truck dissembled so I don't know what they were for. Fill them or leave them? I'm now working on the larger holes, so they will all go away for now.

IMG_1938 by Robert Moorman, on Flickr