I've collected 40 or so azaleas over the last 10 years, and have always had better luck when I cut them back hard--to only the selected trunk line(s) and grow new branches on them over the course of the next few years.
Use plenty of organic soil if they're in the ground; top-dress with compost and pine bark. Don't let them flower for a few years to get them growing strong.
The tree in the third photo looks like it's pretty dry; in the middle photo, it's at least showing some new growth above last year's red leaves.
The white, pitted leaf surfaces are probably caused by azalea lace bugs. They suck the sap and chlorophyl out of the leaves, weaking the tree considerably. Look at the undersides of the leaves, are they sticky? Do you see droppings and little moth-like bugs with clear & black-speckled wings? If you have them, they are frustratingly hard to get rid of with organics. A member of our club recommends disyston (sp), added right to the soil. It's a systemic that he swears by. I haven't tried it, but he says the stuff works, but is pretty strong...use a mask and gloves.
Good luck!