We have a December use year. We travel mostly in December and in March, so it works for us. With a December use year, your banking deadline is the end of July. So if you had reservations in the summer, as long as you cancel them at least a month out, you can still bank them to the next year through July. If you had to cancel after the banking deadline, you would be scrambling to use the points (or rent them out, likely at a discount) before the end of November. You are correct that if you had reservations in November and had a last minute change of plans, you would be very likely to lose those points. This could be even more painful if you had borrowed points for the November trip. For this reason, we tend to favor the Christmas season over going during Food and Wine, but I am sure that at some point, we will try Food and Wine.
How much this matters depends a lot on how much you control your schedule. If you can make firm plans 11 months out, and only have to worry about a last minute sickness, then sometimes you just have to take the risk. But if you are in a career where you might have to cancel a vacation on short notice, it becomes more important to get this right.
Among the travel months you mentioned, if some would be for 2BR mostly and some would be for studios (mostly), I might choose a use year to protect the 2BRs because that would cover more points.
Also, while it makes a lot of sense to pick the best use year for your needs, keep in mind that your needs may change over 50 years, Right now, it is easy to travel in March with a 1 year old grandson and his family, but when he reaches school age, we might be looking more at the summer months.
You just have to make the best decision you can. For someone to lose points due to a bad use year is rare, but as you read on the boards, it does happen.
It is possible to buy
trip insurance through an insurance company affiliated with Disney, but it will only cover the cost of Maintenance Fees, which are maybe ⅓ of the value of your points, so we don't bother. However, we are doing an Adventures By Disney vacation and we did get trip insurance for that, because it is a large amount and all covered.
