Ok, so North Texas and SMU are out of the question, as well as TCU. Anyways, back to UTA, the Rangers Ballpark of Arlington might fit, just as long as it will hold up the FBS minimum of 30,000 seats in the stadium. If it's pretty tight, even better, just some minor tweak modifications or so; giving time for UTA to expand Mavericks Stadium (if the school chooses to add football, plus having money to invest on said expansions, etc.). Might be worth a try, who knows? Besides, look at UTSA, who's also a recently new football program like South Alabama, they have the Alamodome (an off-campus stadium for Greater San Antonio) and put some 25k-30k butts on those seats of a nearly 50k-60k facility.
I understand you have the idea in mind about the Rangers Ball Park...but, the owners are not going to reconstruct the stadium, which holds plenty of people, to fit football. When there is a brand new world class fb stadium....next door. It just doesn't make any sense.
There are High School stadiums that would work fine...in the mean time...if that was the problem stopping fb from being sponsored, which it isn't.
UTA just doesn't want fb. So, trying to work out issues that aren't really problems seems self defeating. When the main problem is support from the school, itself.