First, you are in Texas, so the ONLY species of Tilapia you can stock in open water is Mozambique. Also, to remain legal, you need to retain a receipt stating the species and weight or number of fish stocked. If the market says they are just "Tilapia", walk away.
As several people have said, the "Food Fish" are almost certainly all male, so there will be NO forage production. Also, extremely little algae consumed since without babies, the stockers can't eat all that much. Chances are also very high that if they are a light color, they are Nile Tilapia, so even if they were mixed sex, Niles reproduce at a lower rate than Mozambique. The food fish industry and pond fish industry are nothing alike really in what is raised. Fish raised for ponds are far more labor intensive, so therefore more expensive. Pond Tilapia are also fed a lot more than food fish because the babies and females are kept healthy.
As for being stressed or banged up...the biggest reason Nilotica Tilapia are sold in stores, live, is that the light color hides missing scales. Blue and Mozambique are normally quite dark and missing scales stand out big time on live fish. Tilapia are tough as nails or shoe leather, so I doubt stress would be a big concern.
