Bees do this with incredible specificity AND communicate their knowledge with almost no brain at all.
Long distance walking--not to say hunting, but the opportunity was there--predates big brains by at least two million years.
Yeah, but ignoring the bee thing, or the army ant thing (which I think is mostly chemistry), hunting in packs requires social cooperation over a long period of time. It can take a day or two to chase a deer to exhaustion, as its sprints become progressively shorter. This goal-oriented cooperation requires some brain size. We've got it. Wolves (and dogs) have it. It's been said that this is why, of all the beasts in the world, we get along best with dogs.
On the hairlessness issue, I think I agree with you. Evaporation of sweat is important. Dogs pant, we sweat. Bye bye pelt.
And this has been known for as long as I can remember. Why, then, are the estimated times for ancient human expansions always so long? I mean, once humans had set foot on Eurasia from Africa, why wouldn't they have wandered over the entire continent in just a few hundred years?
Back to the beach. Wouldn't a diet of high protien seafood supplemented with seaweed and grains contribute to brain growth? I'm a layman here to learn and the idea I'm getting is that apes live in the jungle, bipedal hominids evolved on the savannahs and plains, but the very small group from which modern humans decended made the first of their two major evolutions on the beach. The 2nd "great leap forward" occured after glacier melt opened the Eurasian rivers.