[regfortruegoo]

I like the way Jazzy put it: prevention is key, but its still not a breed you turn loose with a bunch of other dogs and kick back for a few beers. Well said.
Even with non-bully dogs I am careful what kind of dogs mine are exposed to and in what environment. Even the friendliest dog isn't going to like every other dog it meets.

Even if he hasn't been around cats you could definitely acclimate him to them, BUT I would absolutely introduce to your cat(s) before any decision is made. When I adopted Lily (anything Siberian and/or GSD is notorious for insane, cat eating prey drive and a lot of shelters/rescues won't adopt those breeds to people with cats period depending on the dog) they let me bring my Missy cat to the shelter in her carrier. We let Lil's sniff around the carrier and needless to say it was good. I was very careful and monitored their interaction carefully for the first few weeks, making sure the cats had an escape route. Lily is weird for the breeds of dog she is... she'd bring home all the stray cats I'd let her... luckily my cats are very cat aggressive which any chance of more cats being added in.
My other dog on the other hand, while being awesome with my particular cats, would definitely try to kill or at the very least chase any other cats besides mine. I've been working pretty hard on her not going completely nutso when she sees a cat loose on the street. She's actually a little scared of my cats if that tells you anything about my beastly cats.

Nope. I would not be comfortable with that. What happens if the dog sees a squirrel and bolts for it? Or if someones loose dog runs up? Or if the dog tries to fence fight dogs you are walking past on the sidewalk? Hell, I have to exert some serious effort to hold her if I allow or there is just far too tempting of a squirrel or duck taunting Lily. She's drivey as hell, but there is nothing quite like bulldog drive... they are even more intense than my little psycho.

I ran into someone letting a child walk a 100+ lb coonhound once and it broke away and ran up to Lily... what if he'd run up to my friend's Rhodie and not my friendly girl who loves the boys? It would have been seriously, seriously ugly to break up. Especially since the parent in question has a sickenly huge herd of small dogs on leashes herself. Not worth the risk for the dog or child IMO.

Adorable dog btw. It would be cool if everything panned out for you guys because he looks pretty awesome!