My concept for generalized humanity, in contrast to other species options like elves, dwarves, dragonborn, etc. is:
Wanderlust.
One of the things that seems to have distinguished homo sapiens sapiens from our neighbor subspecies like neanderthalensis and denisova is that our populations wandered. A lot. Sailing across the horizon simply because there was a horizon to sail across, even though that was often a dangerous or lethal proposition. Some anthropologists and paleontologists even think this is part of what made anatomically modern humans succeed so well.
Humans are also excellent persistence hunters, have a ferociously strong pack-bonding instinct (seriously, we'll personify damn near anything), and frequently see so many patterns in nature we may as well have a species-wide case of apophenia.
So, I'd make "Wanderfolk" represent these characteristics. Greater endurance (perhaps a resistance to Exhaustion or similar mechanics), an easier time using diplomacy and insight in ways that relate to other species, and superior investigation skills with a slight propensity to see more than is really there (e.g., perhaps a 1/SR advantage on Perception, but worse consequences for failure, or partially wrong/mixed fact-and-fancy answers even on a success if you roll doubles.)
I'm fine with preserving the "get a bonus feat" thing, as that's a perfectly reasonable choice and dovetails at least a little with the above.
By comparison, dragonborn, who develop more quickly than humans and thus lead longer adult lives, and who have to spend far less time, y'know, worrying about pregnancy and such? They're much more about building grand and tall, rather than seeing what lies beyond the horizon. They have far less pack-bonding and far more friend-(or foe)-making interest (both are gregarious but for different reasons), and dragonborn are physically stronger and heal faster, but don't have the hours-on-end endurance humans do. Clan and legacy are everything to the typical dragonborn, while most humans are rather more individualistic; not that there aren't exceptions, of course, but these are the general trends.