There is a saying often repeated on here, that the only silly question is the one you don't ask. None of us started as experts, and most of us still aren't!
If you get some skill at using the two search functions on here, you may find the answers to many questions. They can be frustrating to use, we know, so there is usually someone around who will jump in. Posts move fast, though, so you might also ask a question that no one answers; it happens.
Chickens in the rain: All they need is a place to go if they wish. You would be surprised how wet they will get and be perfectly happy, especially in a warmer climate like yours (and mine, much of the year.) For chicks, I might be a bit nervous, too, about the rain, but I'll bet they would be under cover on their own if they were chilled. Chickens do need to be able to get somewhere where they can get their feet dry.
Chickens don't get colds. They do sometimes get respiratory illnesses, and many of them are viral, but not from being wet; these diseases are contagious, carried by other birds. Actually, people don't catch colds from getting wet, either.
Armadillo will not bother your birds, and usually vultures will not, either. Hawks are more likely to take a young bird than an adult. Our snakes will also not usually take mature birds, but will steal eggs. Of course, there is always the chance of a startled poisonous snake striking, and we don't have large constrictors, except in places people have released them. You might have more trouble with the mammals -- and maybe rodents, I can't even remember the names of those larger ones you have, much less whether they take live prey or just eat vegetation. Nutrea?
You might find it educational to talk to some others there who let their chickens roam, and see how many losses they have, and what animals seem to be the culprits. (Do monkeys take chickens?) You should have less problem with the local critters overpopulating their range, causing them to encroach on people, than we have, or I hope you will. There are plenty of predators where I live that will take a chicken, but most seem to have enough prey in wilder areas to keep them satisfied. You might find yourself considering a fence for your cleared area, in time, maybe an electric one.
And you might find you don't have to do much clearing to have goats and pigs. As a rule, snakes tend to vacate when goats are around, I have heard, at least around here.
Lots of info here in the learning center (top of page) and the FAQ section.
Looking forward to pics!