Seems I have forgotten how to use points! Help!

Yes if you cancel your reservation 31 days or more in advance and you're still within your banking deadline, you can bank all of those points for next year.

If you want to switch some of your days to Animal Kingdom, you're going to have to have more points to cover it. Or you could split your old key West stay into two reservations. Then the part you want to switch to Animal Kingdom you can switch at 7 months or wait list. A wait list will not be confirmed until all the nights are available and you have the number points to cover it. That's something you have to consider. The points needed for old key West and Animal Kingdom may be different.

I have a reservation booked at Saratoga Springs in early December that I plan on trying to switch at 7 months to Boardwalk. But I know it will cost a few extra points. So I'm making sure there are points left in my account to cover this. And most likely it will be waitlisted. But I'll activate and waitlist until 31 days. After that I'll stop trying so that I can bank any extra points into next year.