I'd say that UTSW is quite competitive (likely the most competitive of the region) and a step 1 as high as you can will only help, 230 seems a bit too low (but who knows). Without turning this into a program review, I'd say that other Texas programs are easier to land with step score closer to the bottom of the range you gave. As for Arizona here is what my opinion is:
Mayo phoenix, the program started 3 years ago. I liked their philosophy and the staff involved. I also loved the location. Currently probably not seen as a "top program", but I think it is a solid one. The staff seems quite invested. The current first residents (R3s I think) are two ladies who originally were surgery residents (one in Ortho and the other general I think) who transferred out of the surgery residency within Mayo. I recall them saying that they received a lot of help/support from all parties involved including the directors they were leaving. All that to say that there is some support that would not necessarily find elsewhere. It certainly doesn't attract the same type of students than UTSW or academic institution. They are still casting a "wide net": on my interview day there was 1 (or 2 perhaps) students for the Caribbeans, so they remain open and I would assume that most with a decent step 1 who would be interested could potentially have a least an interview.
U of Arizona: this program is really underrated I think. The level of research and the stuff that comes out of there is quite cool and I see them on the up trend. While technically not a top program now, I think they may well become one at some point. Again, it turns out that there was a caribbean's student among interviewees so they too remain open to good students showing interest. This program is definitely an excellent alternative, particularly if your step 1 falls under the cutoff of the top programs, and if you are more interested by an academic/research setting.
All in all you are still an MS2. While I do think Radiology is the best specialty in the world, give yourself some time and remain open to other possibilities. I have known many students who changed their mind (I almost did as well). Just try to enjoy your education and see as much as I can while you can. As for looking at programs it is really a shot in the dark at your stage. Just get the best grades and step you can. Then you will have a choice.