The lot of stuff to do is a lots and lots of little things that add up, plus add in to it the stress of getting married, and the desire for everything to be perfect. It's the quest for perfection that turns many brides (and grooms) into Bridezilla and Groomzilla.
FOrget listening to the sisters, the wedding should be about what you want. If you want your dog to be the ring bearer, and you want a quiet ceremony on a beach some where, then do it... You don't need to turn it into a three ring circus if you don't want it to... You just have to keep listening to each other and tune others (including me