I don't know why I engage with you. You are not satisfied until you hear what you want to hear.
1) Hispanic or Latino is very broad. If you have any Hispanic/Latinos friends they will tell there are white Hispanic/Latinos and black or afro Hispanic/Latinos. I'm not Hispanic/Latinos, therefore I cannot speak on what they would call someone like Zimmerman, Hispanic/Latinos or white. As far as Obama, from the black perspective a large percentage of bi-racial blacks consider themselves black. However, for the most part it is based on the whether that person is on the darker shade or lighter shade. Number 2, society puts them in a particular category also. Haven't you heard of the "One drop rule". I know you hate to hear this because in your world, racism doesn't exist. But during Jim Crow, a person was considered black if they had "one drop" of black blood. (Don't let any young white kids see this as they may have nightmares for the rest of their lives). Anyhow, since Obama is on the brown or darker shade, most people and apparently himself identify as being black. On the flip side, remember the actress/singer back in the day named Carol Channing. Her paternal grandmother was black. Channing was so light skinned, as a teenager she decided to "pass", as the term was called, for white most likely to further her career. Because of white privilege, that you don't believe exist, some very light skinned blacks and Hispanics/Latinos for that matter try to "pass" as white in order to advance their careers or fit in socially.
The bottom line it is not according to me, it is a combination of society and the person themselves on how they want to be identified.
2) We all know if Martin was white that Zimmerman would not have stopped the kid. Those who see otherwise is in denial.
3) Not going go through that again with you.