A lot of what you are going to be able to get at 7 months is going to depend on what you are asking for and when. During slow times, you should be able to get Bay Lake about 75% of the time at the 7 month mark, during busy times about 5%. You'll have better luck with 1 bedroom villas than studios or 2 bedrooms. Most of the time when you can get something it will probably be Lake view.
I think that a 50% success rate as a gauge would be close at the 7 month mark.
My thinking of the $40 Vero points is that it may be a good deal up front, but they have some of the highest maintenance fees of any
DVC. I don't have the current rates, but I believe they were in the high $6/point range. You can get other resorts for about $2/point less. This may not seem like a big deal, but amortize this over then next 30+ years and it no longer is a deal. Assuming a $2 point difference and a 200 point contract, that is $400 per year, or $12,000 more in maint fees over the life of the contract. You can start spinning interest rates into the equation, but you can see that it adds up.
Now there is no guarantee what is going to happen in the future with maint fees. I think that we can assume that they won't be going down, but they may not go up at the same rate as other resorts.
If you want DVC for visiting DisneyWorld, I'd suggest you purchase an onsite property. We went with SSR. Contract goes an extra 12 years too giving it more resale value. This way, you can always get a place onsite at the 11 month mark and move at 7 months if available.
Unless you would be happy staying at Vero Beach, I wouldn't buy there. (Just my opinion)