Total cost of attendance before scholarships is not different enough between the schools that it should impact your decision. Unless, of course...
...you live in one of the other cities. In which case, it then makes sense to examine if that really will be a good thing. The place where you currently live -- Is it free? (ex. parents) Or not free? If it's not free, it's not really different than paying rent elsewhere. Is your current residence conducive to being a medical student? You say you live in Houston. That's a BIG city (geographically). Do you live with your parents in Katy or Sugar Land where you're looking at a 45-60 minute commute? (NOT good) Or in West U. where it's 15 minutes at rush hour? Would living with your current housemates be a good thing? (Free home-cooked meals ready when you are?) Or a not-so-good thing? (Family obligations, noise, guilt trips and conflict that would interfere with your studies.) So consider it from all angles rather than chalking it up automatically to the plus column.
A pretty valid observation. Did you LIKE any of the schools significantly more than the others? If not, UTSW is the highest-ranked of the four by a pretty wide margin, and when it comes to your residency options, that will help open up doors. However, if you didn't like UTSW as well as some of the others and don't think you will perform well there, that residency-placement advantage is pretty-much neutralized. Do consider though what type of career you want to have. Are you the kind of person who is likely to prefer the more competitive, higher-paying specialties if you can get into them? Or genuinely NOT motivated by prestige and would sincerely be happy with 'lower status' specialties? If you're certain you're the latter type, ignore the ranking difference.
You don't have any way of knowing what your financial aid package (if any) will be, and even trying to guess will be a wasted effort. If UTSW is rumored to be more generous, that's about as good a recommendation as you're likely to get. But with NO certainty, that shouldn't be a major consideration. And frankly, with the maximum potential difference between a 'full-tuition' and 'no-help-at-all' scenario being under $20K per year, it's just not worth worrying about. Other factors (above) are worth more than $20K/year.
UNT (the DO school) and LSM (Do you mean San Antonio?) ? UTSA did have a very strong match list in 2017, and I expect UNT's match would be among the very strongest for DO's, but to claim that they are better overall than UTSW is probably inaccurate.
Bottom line -- If you have a fairly strong preference, honor it. If not, UTSW is your best bet.