alcohol - yes we probably came across fermenting fruit at times. Probably not like a glass of wine on a daily basis.
coffee - likely that our ancestors took drug containing beans, roasted and then brewed them (in non existent cookware)?
nuts - many wild nuts are poisonous (ie wild almonds, raw cashews. Even the genus macadamia has only 2 edible species of 9). They contain anti-nutrients, are high in 06. Would we occasionally have had a few in season? Yes but never in high quantities and on a regular basis. Almost certainly never grind and cook with them.
seeds - same as nuts.
dairy - arguable. Similar slightly to something we have as babies. It's fat is similar to the fat of the animals. But likely better to not eat at all.
veggies and fruits (in high quantities) - Firstly they are seasonal. Secondly, wild veggies don't taste so great, the ones we have now are the result of thousands of years of artificial selection for the most appealing qualities to us. And even at that, the majority of people don't like the taste unless accompanied by something (sauce, spice, meat etc). Modern fruit has also been artificially selected - wild would be stuffed with seeds, more fibrous and less sweet. You would have it in season (probably gorge on as much sweet as you could), but it wouldn't be a year round thing.
Now I do partake in these things myself, although try to avoid. I like them, they do something for me. But I think it's pretty obvious they aren't totally paleo, why are they any different from grains?
What attracted me to paleo was it's simplicity - base our food choices on what our ancestors ate. Why? Because almost no matter how much we think we know about health, we will always be missing something. We just 'discovered' most vitamins and nutrients in the last century (they have always been there though). How many nutrients do we not know about, or may never know about? The simple fact is we are just a bunch of clever monkeys and our knowledge will always be limited.
Even when we do studies, they can't fully encompass what we are trying to prove, because we can't, for example, lock thousands of people away for their lifetimes, feed them precise diets and then compare the results.
So why should we consume any of the above?