In terms of last minute trip cancellations/rescheduling and the points banking window, you want a UY that begins before your typical travel time. So something like October (if they offer it) would be ideal for your current plans. I think anything from July through November may work fine (July gives you 4 months after your last travel month Feb which still allows all remaining points to be banked). Often people's preferences change so you may want something in the middle that gives you more future flexibility. That said, if you plan and book all your trips 11 months in advance, and never need to last-minute cancel any UY works OK.
BLT uses a lot of points in comparison to other resorts. I am sure that a lot of
DVC owners will want to try out BLT, but many may eventually prefer, again, a longer trip(s) or larger rooms in other resorts. BLT is ideal for MK and monorail resort dining, but there are members that prefer other areas of WDW more than the MK.
No one knows exactly the future demand. Of course sales will attmept to sell you on BLT being the most popular. I do believe that if you only want to stay in BLT, you will want to own BLT to use the 11 month booking window. Inside 7 month booking window, points are points, and it does not matter where you own. (Although BLT may (but certainly not guaranteed) always have the lowest annual member fees. BLT operating expenses per room may not be lower, but the fees get spread out more because you use book with more points per room.)
Yes you can book (at least 48 hours in advance) any of the 3
DDP's (CS, DDP and DDPxP) for all nights of your stay while staying on DVC points. As a DVC member, you do not have to buy any park tickets to buy the DDP (like cash guests have to)
Disclaimer, DVC owners never get "free dining" We already get a heavily discounted room by buying DVC in advance. "free dining" is just a cash room discount.
