It's scientifically proven that mixed-race children suffer from a lot of psychological problems statistically. I wouldn't want to put my kids at an immediate disadvantage, life is already hard enough. So I would never marry somebody outside my race, and thus dating outside my race would be a waste of my time and hers. I also wouldn't date anyone with a serious genetic disease that could get passed onto half my children, or any woman old enough that the risk of birth defects is significantly higher (if she can get pregnant at all). I would not date anyone obese, or a smoker, or diabetic. I'm not a gambler.
As for height, I certainly have a preference, a range of heights I would consider preferable, but I would never let something like that be a deal-breaker. I try to keep my list of deal-breakers to the absolute essentials, those based around health.