I actually really like the racist idea. I think it would be really interesting for Johnny to realize there are parts of the Diaz family's lives that he can't relate to. I also think it would cause him to have some self reflection/growth from the way he treated Miguel in the beginning and other people in the past. I think this particular idea could bring about a great fic where Johnny grows a lot and where we of course get some awesome moments between Miggy and Johnny.