Finger foods and desert reception?!
Answers:
It's your day. Make sure that on the invitations you put "light hors d' oeuvres" will be served. I am a Director of Catering and my suggestion is that you factor 4-5 pieces per person on the H.D's and depending on what sort of desserts you are serving ie; petit fours, chocolate fountain station etc etc. The wedding cake is all that is required for Desserts. Etiquette wise... this is a Sunday afternoon event if your wedding ceremony BEGINS at 2:30pm you probably will not be out until after 3:30pm placing you close to the dinner hour for some. Hope this helps and feel free to e-mail me here if you need other assistance.
Psboston7
Do what feels right.