Unless there have been changes I don't think it is possible to use the MYW dining plan without the entire group using a package. From how I understand it it is all or none. Everyone must be a part of the package. MYW dining add-on is only for package rooms, not AP discounted rooms and only for all members of the party.
As for sharing meals--I'm sure there would be enough food for four since the plan has the sit down feature with appetizer and dessert as well as the entree--counter service may be a little tight depending on the appetites of those dining and snacks, I doubt there would be room to share since it is only a scoop of popcorn or a single serve ice cream treat.
Have you considered purchasing the DDE with your AP it is a perk for $50. and would take 20% off all meals at sit down restuarnats and some select counter service locations. the 20% includes many things not included withthe MYW dining plan since it includes alcohol and specialty drinks. We have found that we are not "forced" to order foods we don't really want (ie 4 appetizers and 4 desserts) and the savings is almost like getting one meal for free every time we use it.
