Is the soil moist when you insert a finger to a depth of 4"? It may be getting dry spells and wet spells due to the summer temperatures. Evenly moist soil should be the goal. Azalea roots grow mostly in the top 4" of the soil and are very tiny and fibruous. This area also tends to dry out fast during summer when the winds pick up and the temps regularly stay in the 100s. Long periods of drought will weaken plants, allowing them to suffer from other ailments like fungal infections.

Overwatering can also cause problems and root rot so try to water when the soil starts to feel almost dry.

Some wilting of leaves is ok provided they recover when the sun goes down or by next morning. Extreme looking wilting episodes however should be dealt with immediately (ie, apply about 1 gallon of water) since a rootball that dries out may be difficult to save (of all things, they actually tend to repel water so you have to drip irrigate them or dunk the shrub in a container full of water).

What kind of soil do you have? Most locations the DFW Area require planting in raised beds because of the clay content.

I noticed no mulch under the shrubs in some pictures; I would maintain 3-4" of acidic mulch past the drip line. I would also try to water with rain barrel water (or something similar) as our water is as alkaline as our soil.

It is common to have some leaf spots this time of the year. And watering the leaves can cause this too. I could not get a good grasp of how many leaves in the shrub have them; if it is only a few, you may not want to take action except to use good sanitation techniques.

Examples: never wanter the leaves; water the soil only and do it early in the mornings; dispose of plant debris under the shrubs; throw away infected leaves in the trash instead of the compost pile; allow for good air movement between plants by separating the shrubs; etc

Fertilize if your soil needs it but stop by July so tender new growth does not get zapped when winter arrives. Azaleas tend to feed off the decomposing mulch and are not heavy feeders. Some Hollytone or cotton seed meal in Spring should be fine.