Personality isn't racial, it's cultural and individual. Why are we so quick to apply ideas of racial essentialism to science-fiction characters that would be considered monstrous if applied to humans?
If by "the Vulcan in Enterprise" you mean T'Pol, she was initially hostile toward Captain Archer and his crew, but she ended up developing a strong loyalty to Archer, on a par with Spock's loyalty to his commanding officers. And any hostility she had was a product of her cultural upbringing; remember, she lived a century before Spock, in a galaxy where Vulcans had been the dominant culture for some time and humans had yet to prove themselves worthy. She had a condescending view of humans because of that. It wasn't a function of her genetics.
As for the question in the thread title, the conceit from the beginning has been that Spock's "human half" makes him more emotional than other Vulcans. But that's self-contradictory, because we've also been told, nearly from the start, that Vulcan emotions are so intense and savage that it necessitates their rigid code of logic simply to contain them. At best, the "human half" references are figurative; since he was raised by a human mother, influenced by her emotionalism and human values, that would affect his personality differently than if he'd been raised by a Vulcan mother and father. But it would be illogical in the extreme to attribute it to genetics. (The fact that Spock and other Vulcans routinely do attribute it to genetics, ignoring the intrinsic contradiction, proves that they aren't as flawlessly logical as they pretend.)