I spend most of my time with my dogs, i could probably write at least as much as you do, but just wanted to sum it up !teeth
My little bulldog is a little less roly-poly than most, tight, well muscled and likes to jump. She's only about 15" at the shoulder, but can spring about 4' in the air straight up when she's after something i have. She also doesn't have any trouble in the heat, spends most of her days outdoors in the summer, just baking herself in the sun. We can hit 100F here with humidity.
Tosas vary in degree of dog aggression, depends on genetics and to a large extent socialization. I take my dogs to dogparks when they're less than 1 year, so I don't have major problems with aggression. I still can't take them around other unfamiliar off leash dogs once they're mature. ie. i would be in big trouble if i took any of the adults to a dogpark. My male gets along with most dogs, but hates intact males of any size and temperament. It's like the smell of testosterone just sets off the gladiator. He's fine with HIS puppies though. I think he would bite a female dog if she really wanted to fight, or if she tried to be aggressive to me. My females are a bit milder, but very dominant with all other dogs ie. tail and hair up, a fight just waiting to happen if i wasn't careful. All my dogs get along extremely well, i don't tolerate any dominance or growling etc. in my pack.
I've known a few Tosas who weren't dog aggressive, and some who are the poster children for BSL. Most Tosas have manageable dog aggression if you train and socialize them properly.