Maybe you need a hybrid or "bridge" program. Avoid muriate of potash--go with potassium sulfate. Use only plastic-coated slow release fertilizer; at least 50 percent coated; 70 to 100 percent coated is better. Blend this with an organic fert--Barry at Phasthound can help you there. You may wish to go with 100 percent organic slow-release during the hot summer months. Organic is non-burning, restores the soil biology and may reduce disease. Of course, if you want to kill weeds or chinchbugs, you need a license.
You may want to add aeration and/or sowing of high-quality disease-resistant seed during whatever season is suitable for that in Austin. Overseeding of Bermuda with perennial rye in fall is also a possibility. And during those tough years maybe offer to do the green dye for grass, (messy, but nice profit).