I think the throat veins are misguided. I understand wanting to make the fucking intense. But part of the allure of a futa is their supernatural sexual prowess.
It would be hotter if she fucked like a supernatural machine and never broke a sweat. Her popping a bald boomer cop aneurysm and turning beet red and sweating makes her seem unfit and weak. Just express her sexual potency through the action, it's hotter if she isn't flustered than if she is.