Looks good, same engine my son has in his 05 Explorer XLT 2wd. That said, I don't think he's getting 20mpg in mixed driving. That sounds very good.
As said, G-05 is the way to go with the coolant, readily available at NAPA's or the dealer for a reasonable price. As said though, whatever is in there (doubt it's G-05) should be ok for a while. Just next time go with G-05.
I looked at the plugs/location on the Explorer. For me, it would be a tough stretch over the front of the vehicle to get to all of them. That plus based on my reading, removal can be tricky, so I'd leave it to a dealer or experienced shop.
The Explorer has no trans dipstick, not sure about your truck. For me that means letting someone do the trans service.
And, the Explorer has primarily seen 5w20 MC syn blend and MC FL-820S with 5k OCI's which is consistent on the OLM.
Sounds like a great deal for 8K, congrats.