My apologies, but what bearing does the distinction between “race trait” and “racial trait” have on the question I asked? Both the FAQ and the passage in the book use the term “racial trait” so your distinction doesn’t apply to my question.
(Additionally, I don’t see your distinction between “race trait” and “racial trait” in the rules, so if you could provide your quotation/citation from the rules or an FAQ, I’d be appreciative.)
My question (which I’m not certain was adequately addressed) is whether in the rule, “This racial trait replaces the bonus feat trait”, the bonus feat being referred to has to be the humans’ self titled “Bonus Feat”, or if it can be the bonus feat given by the half-human races. I hope you can see the ambiguity in the RAW. The bonus feat of the Half-elves is a racial trait, just as much as the Humans’ bonus feat.
As for RAI, why shouldn't Half-elves be able to take human alternate racial traits? Said traits are still human, and a Half-elf having such a trait simply implies that the Half-elf's human parent possessed that trait. There's no lore reason to forbid it, and I can't picture any situation where it would unbalance the rules.