1. There is no such thing as a "DVC Discount" related to any Annual Passes (No matter what Member Services says).
There are two separate categories (or price ranges) of Annual Passes. The lower price range is for Florida Residents and for DVC Members. And the higher price range is "Tourist", which is people who do not qualify for either of the other categories.
And of the six possible DVC Member AP types, the price difference from Tourist ranges between $115 and $149.
2. Disney does not discount one or two day tickets at all.
3. There are various authorized resellers who give about a 5% discount on tickets. However, if they sell one or two day tickets they charge a premium as they have to pay full price and not the wholesale price for them.