I'd be very concerned on two fronts; firstly who would actually want a Staffordshire Bull Terrier (people should stop trying to make it sound cute with the name "staffie") and secondly if it's from a rescue home why was it in there - obviously broken in some way either by poor nurture or undesirable nature.
Not obvious at all unless you have a particularly blinkered view, dogs can end up in rescue homes for many reasons, strays that either have no microchip or the chip details haven't been updated, owners moving into rental house that doesn't allow pets, owner dies and no-one to take on the dog, owner moving abroad, job loss so can no longer afford to keep the dog, illness/incapacity so no longer physically able to look after the dog.
I hate the word "staffie" so never refer to ours that way. It's not a breed I'd have ever chosen, he was my father-in-laws dog and would have ended up at a rescue centre if we hadn't taken him on (see point above
) He's by far the most obedient and good natured dog we've ever had and I'd happily choose the same breed again. He's never once shown any aggressive traits even in situations with other dogs (one in particular when a spaniel sank it's teeth in to him, not the first time the same spaniel had bitten another dog) doesn't chase anything other than frisbees and tennis balls and has generally done a very good job of changing other peoples opinion of the breed (generally people who've no experience of the breed and get all their information 2nd/3rd hand or from the Daily Mail)
Dog ownership is very popular where I live and makes for interesting viewing, the majority are well trained dogs with responsible owners sadly there's also a fair few ineffectual owners with ill trained or untrained dogs, fortunately they're usually on a lead as they daren't let them off. I've been asked several times about Barney as he's almost never on the lead, I can walk him anywhere and if I tell him he'll stay at my heel until I tell him otherwise, most end up disappointed when they ask how long it took to train him, 10 years is the answer, how old is he? 10 years
. Training never stops.
As for banning certain breeds you're (not you specifically) focusing on the wrong part of the problem, ban the owners. what will happen if you ban the breeds? the owners who want a dog as a status symbol will choose an available breed, rottweilers, dobermans, german shepards etc the problem wont go away. If you mistreat or train any breed to be aggressive then that's what you'll get.