Thanks for your questions and your sincere concern for your Amazon’s safety.
I have had companion parrots for 30+ years and for 7 years had an outdoor breeder aviary.
I currently happily share my life with a single Timneh African Grey, Timmy, who is a rescue from a bad home but tame and loving even after what he has been through (including being batted against a wall, losing consciousness).
I do clip wings slightly to prevent upward flight, unlike Mitch and Catherine.
But that is a personal choice and I love to hear of flighted birds. So I am not truly an advocate of clipping, it’s just best in my situation.
I live on the east coast of Central Florida, just south of Kennedy Space Center and only 4 blocks from the ocean.
This area is sub-tropical, just as your weather is right now in Texas. We also have summers much like yours (hot, hot, hot and often dry), though you probably have colder winters than we do.
The only concerns you should have about your bird outdoors as long as it is safely caged or in a harness or flight suit is it consuming standing water or any grasses that could have been sprayed with pesticides and the ambient temperature.
Cool strong breezes can cause respiratory infections or “colds”. Overheating can kill quickly if not recognized and controlled. Consuming or chewing on items that may not be bird safe such as metals, pressure treated wood, and similar items could cause poisoning that could kill the bird.
While we humans are plagued by concerns such as West Nile Virus, Zika Virus, Malaria and other maladies due to insect bites from mosquitoes and are plagued by other stinging insects, my research and personal experience have revealed no diseases transmitted to parrots via bug bites.
Consider this: our parrots evolved to live in pest-infested jungles with insects we’ve never encountered, yet they remain healthy.
On good weather days, my Timmy and I go outside in the unfiltered sunlight for at least 20 minutes to help both our bodies produce needed Vitamin D naturally. It also helps us absorb the vitamins we consume in food.
While I get bug bites if I do not protect against it, Timmy never is bothered.
Perhaps it is the way parrot feathers create a tight, thick layer of protection between the environment and their skin so that biting pests can’t penetrate the feathers.
The only pest I am aware of that you should worry about is mites. The only way your Amazon would get these is if you allowed him to play extensively in outdoor trees where these pests live.
Wild birds live with them but you don’t want to bring them inside your house as they do cause itching in birds. This is why you should wash and bake at low temperature for 20-30 minutes any branches brought indoors for perches. This ensures any mites present are killed.