OP--There's a lot of good information on this thread. I've never rented points for a few reasons. One is that I don't want to be locked into a reservation so far in advance of a trip--or, really, at all. That's why I always book a room-only reservation, which can be canceled up to 5 days before check-in. Even after that 5-day mark, you're charged only the one night's deposit if you end up having to cancel.
I've had a trip where I had to completely rearrange the trip twice less than a week before arrival (weather/transportation issues) and doing it with my WDW reservation, made through WDW, was incredibly easy and painless. If I had booked points, I woudln't've been able to move the dates at all and I would not have gotten a refund. I've also had a trip where I had to leave earlier than planned. If I had booked points for this trip, I would've been out the entire amount of the stay. This could happen with WDW as well, but the front desk was very understanding and charged us only for the days we were actually there.
Yes, you can buy
trip insurance, but whether it would cover your particular reason for needing to move/change/cut short your reservation is another question.
WDW almost always has discounted room rates. Last year the general public discount for dates in September came out around the 3rd week in April. Check out mousesavers.com, which has a lot of information about this.
For your first time staying onsite, keep it simple. Book it yourself, through Disney. Take a look at all the different resorts and price ranges, decide on what you can afford and what you like Read allnears.net and mousesavers.com.
And have a fun trip!