Based upon what I have seen with respect to the University of Florida, I think that being a URM is a significant advantage at a public university.
However, some states have their own rules regarding affirmative action. For example, I think that in Texas, they take you if you are in the top 10% of your high school class, even if the high school is not the greatest. Indirectly, that helps inner city URMs.
Also, if you can afford to pay the OOS tuition, that is a big plus, because many states are hurting for money.
Why the concentration on public schools? Private schools are probably more likely to give you aid, especially if you apply to a private school a little below your pay grade.
I agree that you should apply to 20 schools, but applying to too many public schools is probably being redundant.
My friend's daughter (white), got into almost every public school she applied to. Probably the admission standards at many public schools are roughly equivalent.
So I would say that you are on the right track, but throw a few more "reaches" in there.