1- in America you would say 'can I pet your dog?' in England you would say 'can I stroke your dog?'. 'pet' and 'stroke' mean the same thing. It would sound strange if you asked someone if you could 'touch' their dog.
2- yes, you would either say 'he is a cross between a husky and a bulldog' or you could also say 'he is a husky bulldog cross'.