i agree with most of your answers already... except for #4... there is no mistake... i know what everyone is wearing in the immediate family and wouldn't have it any other way... right down to the grandmas....
if you would have had a receiving line where each guest could speak with you, you may not have had this problem... the bride and groom should easily move about the room without a care... but no, they should not be so expectant of your attention or definitely not sit in your chair...
i would hate to think that my cooking and or cleaning skills ( or desire to do it at all ) would make a significant impact on my finace's desire to marry me... shallow....