UY get's needlessly complicated.
The most important thing to know is that it is in your best interest to travel early in your UY. Do not worry too much about the Why part yet, but it has to do with Banking, a form of "insurance", etc.
This of course is only relevant if you travel at the same time of year, or at least tend to.
If you plan to usually go in December, an October UY would be the best (there is no November). February would be the worst. (There is no January). If you travel in "the fall"...an August UY might be best.
So the answer to your 7 or 11 month question is neither. 1-2 months is best.
I have to disagree with the PP...I do not see December as your best bet for UY if you want to travel in the summer by any means. April or even June would be better.
As far as prior years go, realize, that while the calendar says 2017, unless you have a February UY, almost all
DVC Members are in their 2016 UY. People with a March UY will be entering 2017 on March 1st. So, for many (most) contracts, 2016 is the current (use)year. Heck, a December UY is only 2 months into it's 2016 year!
Home resort may or may not be important depending on when you want to go. Also home resort is only important if you take advantage of the booking window. If you always book inside of the 7 month window, all points are equal, home resort means nothing.
However, if you want a studio at Beach Club or Boardwalk during Food and Wine, 11 months is everything! A studio at the Grand Floridian early decemeber??? 11 months out at 8 am on line might not even get you one. Want to go in September? 7 months availability is often wide open. One bedrooms book the slowest.
I personally go with the "Buy where you want to stay" philosophy. I can also accept the "Buy where you would not mind staying" school of thought. But, if you do not care where you stay, willing to take that may be available at 7 months, then you should buy SSR, as it is the best value out there.