I have noticed some problems with my peach trees and need help diagnosing
them. (I am in Austin, Texas)
I just recently moved into this house and do not have any prior experience with
peach trees.

The leaf spotting is probably a fungus. You need to contact your local
extension agent, because the right spray and timing differ in various parts of
the country.
The other trees seem to be suffering from malnutrition & lack of water,
probably exacerbated by the heat. Make sure your trees are well fed & well
watered and you will be more successful.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)