I will assume that your home resort is not VWL and not BCV.
If you reserve your home resort at 11 months (let's say it's SSR for the example), you know you have a place to stay.
At 7 months, let's say you are unable to get the first 3 nights at BCV (and so ask to be waitlisted). You are able to get the last 4 nights at VWL, so you have MS cancel the last 4 nights at SSR and reserve the VWL nights.
Now you have the first 3 nights at SSR and the last 4 at VWL. If the waitlist for BCV doesn't come through, you just stay at SSR the first 3 nights.
You only commit points when you actually make the reservation - no points are needed to use the waitlist.
There are two ways to use the wailist - be sure to tell MS which way you want to go.
First way is auto confirm. If day(s) become available, MS automatically reserves for you and sends you a confirmation letter.
Second way is to have MS call you when something comes trough - I recommend this if you have a back up
DVC ressie that you need to cancel to make the "waitlist ressie ". MS calls you and you can say yes or no at that time to accepting the waitlist day(s). If you aren't home and have a message machine, MS gives you until close of business next day to call back. (Not sure if they try more than once if you don't have message system). When you talk to MS you can cancel the old ressie to get points to make the new ressie.
Risk in using the waitlist is if you ask to waitlist for individual days - it's possible they won't all come through and then you might have to move back and forth more than you want to do. You can waitlist for all the days to come through at once, but your chances of getting what you want are less this way - MS will not hold a day for you while waiting for other days to become available.
HTH and doesn't confuse you even more.
Best wishes -