Nope, not a single regret! My only issue now is not getting more, and More, and MORE!

But, to address your questions....
* the smell in hot Georgia summers
Smell often comes from improper ventilation in the coop, so if you plan ahead its not too bad. I have windows that I open in spring/summer, close in our cold northeast PA winters. I also scatter a layer of pine shavings in the coop. This helps a lot, and makes it easy to clean out. With only 5 chickens the smell and poop would be manageable.
* dealing with all the ways they die - sickness, predators, accidents, killing each other
Well, this is an inevitable part of owning any animal, but there are plenty of things you can do to minimize issues. Since you are in a development, I wouldn't recommend a rooster. Hens don't do the fighting and I've never had hens kill each other. If you get all your chicks together (not adding in animals from unknown sources) the chances of illness are cut way down. predators are always a factor, but in your development I would think dogs would be the biggest issue. Just be sure you have a coop that is completely secure with a top on it so they are safe at night. The activities of the neighborhood and your presence will most likely keep away most predators. I live in a heavily wooded area without people but with hawks, eagles, racoons, the occasional bear or fox, and I still haven't lost a single chicken to a predator.
* chicken mites
As long as you have enough space per bird in the coop you should be fine. If you let your chickens roam around out in the orchard, they will take dust baths in the dirt and solve that one themselves. Again, I've never had an issue with mites, except for a few silkies I rescued from a bad situation.
* pasty chicken butts and all things related to poop
Weeeellllll, this one is harder. If pasty butts really are an issue, don't get chicks. You can buy your chickens as pullets, or find older birds on places like craigslist.org. But pasty butts are a big deal - usually solves itself after 1-2 days of pulling off the dried poop. Pen poop is pen poop. you can't avoid it. Putting down pine shavings in the coop helps manage it, cleaning the coop out, and giving your birds space all make it much easier. In the winter here my birds stay in their pen and the concentration of birds in the smaller space makes the poo situation noticeable. But in the spring/summer/fall I let them out of the pen and they run around 1/2 acre. The poop droppings are scattered all over, fertilize the grass and I don't even notice it.
* trying to find someone to care for them when we are out of town, or would we never get to leave town again?
I free feed my chickens - a big hanging bucket with feed - so I can leave for about 3 days before I worry. The eggs will stack up, but I'm ok with that. The main issue is to make sure they have enough water, especially in hot GA summers. Once you get the hang of your set up and how you like caring for your chickens, you can figure out the holiday care. I go away for a week or so at a time and have my neighbor check on the birds every few days, add some food and water, and they get to keep the eggs. Works well!
* Initial setup cost (mostly the time and money to build a coop that would not be an eyesore)
Ha! the actual set up really doesn't need to cost much, but we all go a bit bonkers with design of our chicken mansions

All you really need is an enclosed coop with perches and nesting boxes and a door to the outside, an enclosed outdoor run/pen, food, and water. How much you spend is entirely up to you. An easy start is a used shed with a chicken wire pen, but there are zillions of ideas out there.
Get some chickens! they are awesome and will change your life!