Can I book a room with the discount in September 2017 @ Old Key West by phone and get the dining standard plan for free? I'm not a DvC member or AP holder.
No. You NEED to book a package with the conditions provided by WDW: Package including room and tickets. Vacation minimum three nights, ticket minimum two day park hopper.
You can't stack discounts. You can get a room-only discount or you can get a package with free-dining (room full price, 2 day park hopper tickets for all, 3 night minimum stay). At this point you'll need to see what is available for your dates as well, as the number of rooms for each offer is limited.
No it has to be a package, room and tickets. Obviously if you have free dining, you will need park tickets - you're not going to eat all your dining plan in the food court! Not that you CAN, but you see my point...