tofu

1.  normal, usually friends or co-workers who are not too close to you.  they may not want to enter your banquet, since they need to prepare gifts and it is boring(they don't know anyone else).  

2.  depends on the time and schedule.  let say your ceremony starts at 10am and you are going to take pic with each one, then you better prepare some foods.  if your ceremony only takes an hour, probably don't need it.