Depends on which subject you're taking. If you're taking the ang mo in front, then E-TTL the ang mo then recompose the shot. Your flash should only reach the ang mo. As for the shutter speed, depends on the how much background light you want to capture. Arga arga, 1/60, f4, ISO800 should be more then enf to get those people under the street lamp less motion blur and the building in the very far background maybe can also...go try then post a pix...
