A really busy Class B will probably vector you to final everytime for spacing. If it's not extremely busy and they clear you for the visual on downwind, you fly a normal pattern that you would any other airport. If there was conflicting traffic they would not clear you for the visual until you were joining final. Either way you should have the ILS loaded and ready to follow once on final. On a go-around you get instructions from tower. Being cleared for the visual is not an ILS therefore the ILS missed approach does not apply. If you do lose Comm on the go around do your lost comm procedures and return to the airport just like you would any other time.