I think a Muzzle coud make people think he's more dangerous than he actually is!!!!
I have been out with Bear using a Gentle Leader and I've heard people say to their kids, "Oh, that dog is wearing a muzzle, he's dangerous stay away honey." At this point I usually stop and explain what a Gentle leader is..."he's just 7 in human years, just a boy, and he's learning not to pull on a leash"...and let the kids pet bear and give him a treat if their parents allow.
BUT, there will always be people out there who cross the street. I tell myself it's because they are afraid of dogs in general to make myself feel better
I think the Bandana and vest ideas are great and so is getting your dog into a tricks class or dog sport for socialisation and contact with people who know and love dogs of all sizes.