Just some thoughts…
I would apply to both OSU (in-state assuming this is Oregon State) and ASU (known for good merit aid). Having two safeties to me seems like a good plan. Whether you also apply to Alabama IMHO is entirely up to how interested you are in the school. It is pretty far away from Oregon. These are also very good schools – having solid safeties to me seems like a very, very good start on a list.
These are both very good for CS and math. I think that they are worth applications. U.Mass is some distance from Oregon, and will occasionally get snow storms right at the point that you are trying to travel (probably true at Purdue also). However, I have worked with a LOT of U.Mass graduates and the best of them are really, really excellent (I still remember a problem that stumped two MIT graduates and was solved quickly and very well by a U.Mass graduate – who would be excellent regardless of which university he had attended). The campus is also attractive and as others have mentioned it has better food than most (at least based on reputation, and our experience in perhaps 3 visits to the campus).
Both reaches. Both very academically demanding. Do you want to work very, very hard for four years and learn an enormous amount? MIT has a combined major “Mathematics with Computer Science” 18C which to me is about as much fun as one can have when working this hard at a top university.
Stanford is excellent for both CS and math. I loved it (I got my master’s there). I had a roommate and friend who taught me how to cook enchiladas and refried beans, which suggests that they might have some Latino students (at the time he was just a good friend and a strong student, I had no clue and did not care whether he might be Latino). Harvard and Princeton are both excellent for math, and not quite as well known for CS but probably decent (I am pretty sure that they are both trying to fix the “not well known” part). To me the “how hard it is to get admitted” to “how strong they are for CS” ratio does not seem favorable for Harvard or Princeton. I might say the same for Chicago. I do wonder whether or not this will have a favorable impact on the difficulty of admissions for a potential CS major who is academically excellent.
I do not think that you are getting any merit based aid at any of GT, Harvard, Stanford, Princeton, or MIT. They are all likely to be expensive.
For us Northeastern was in a close tie with BU for the most expensive school that either daughter got accepted to (she went elsewhere, then switched to a major that neither school offers).