You are allowed to bring a guest or family member along but they will not be seated together with you. They will be seated at the rear of the hall together with the rest of the other guests.
Don't need to be kiasu and reach there too early, reach on time will do. The event has been designed for late comers, I'm guessing that is why dinner is served first. The ceremony starts only after the buffet dinner.
Not the whole place at Mountbatten CC is air conditioned. They set up a tent with evaporative air coolers and not all the air coolers are in working air condition. While Singapore is in equator with its hot and humid weather, having a tie put on will definitely make you perspire.
