Well, you are in an interesting fix here, aren't you?
Horses can and will hurt you, and you do not have to do anything mean at all for that to happen.
Horses are herd animals, and are constantly fighting for position, by that I mean, there is only one leader, and horses (and all other creatures too for that matter) will kick, bite, run at, and knock into the other horses to determine who will win. And sometimes it is so evenly matched, or horses aren't serious enough about it yet, that it is fairly benign, but that won't last long.
And although you think you are not doing anything to add to the problems, by treating, brushing, and handfeeding them, you are. And the horse that is walking away from you, or taking hay on his terms? Well he is already telling you that you "are not the boss of me" in horse terms.
Stallions also can be very bad to bite, and people have gotten killed by a stallion that decided to bite, and those were experienced horsepeople with some age on them. And those were horses in heavy training and being shown too.
While there are stallions that are kind, those have been handled by horsemen/women who are well versed in horses. Most stallions bear watching at all times.
The adults in your life need to get these stallions either gelded, or run them through a sale and get shed of them.
The longer you work around them, the smaller your chances of not getting hurt become.
Horses make me a better person.