Hello!

[Crowfingers]

Hello, and welcome to the forum! This is a great place to get a ton of advice and answers to your questions.
Most important of all, you are starting your research before getting your snake, this will save you a ton of headache in the future. I'll try and answer some of your questions.
1. Some people will say that ball pythons (or any reptile) are mostly instinct based and don't really have 'personalities' per say, but I think that they do to a degree. I've notice that my little guy is very inquisitive and calm when handled. He begs when it gets close to feeding day, most of the time he comes out of what ever hide he is in when I get up in the morning and home from work at night. He is my only snake, so maybe I'm biased, but I think he has personality
2. I get my frozen rats from Big Cheese Rodent Factory, and have been very pleased with them. I also have experience with Rodent Pro and there quality is fine, cost is about the same between the two. I would stay away from the arctic mice from petco / petsmart, they are sort of mushy and weird, plus more expensive in the long run.
3. I have a bunch of pictures of my little Mashadar on my profile page if your interested. He's a Cinnamon Mojave, which is probably one of my favorite morphs aside from a piebald
4. When you finally feel ready to get your new snake, the most important things to look for are the health of the animal, and to make sure the snake is attractive to you. They can live for 30ish years, so if you get the first one you see, but it's not the one, then you could loose interest. If you are going to get one from a pet-store, make sure that it is a healthy snake of good body condition. You'll be able to search this site for pictures of super skinny, unhealthy snakes from the big box stores as well as healthy snakes so you'll have really good examples of what to look for. I would recommend going to local reptile shows, talking to breeders, and visiting multiple stores to get a feel for things in your area. The breeder that I got my snake from was wonderful.

Sorry for the word wall Welcome again to the site!