I chose the term "complex" in order to gently correct the person I was responding to without stirring the pot any more than necessary. As I reflect on your words correcting me, I still think the term is proper for white people, for the concept of whiteness. If anything, maybe more so. Being Black, or Chinese, or Jewish....all of these are a clear identity which doesn't change over time. Being white, that's not much of a clear identity at all. As your examples demonstrate, whether or not one is white in America varies over time as our racial values change. White people (as defined in our society) certainly take more than their share of all the good stuff our world offers, but that doesn't mean being white isn't complex. The very fact that your "race" can be white one generation but not in another, that's complex rather than simple.
And yes, people have been and are being horribly abused for not fitting the current definition of white. I would say it's more difficult to be considered not white (whatever your actual skin color), but not more complex.