Thank you for all of the tips!
One more question regarding the AP.
If you purchased the AP and then there came out a discount for AP holders, it would be worth it still even after spending the cash for an AP?
Well, you can book AP rates and simply show your AP (or voucher) at check-in. I don't believe you need your voucher to book an AP rate...
One of the reasons for doing it that way, would be to ensure that the AP would save you money. The only way to do *that* is to crunch the numbers.
For example,
if an AP saves you $100 per night on the room, for 5 nights, then you've saved $500 minus the cost of the AP ($439? for an adult). If we assume you were already planning on buying a 6 day, Magic Your Way park hopper pass ($222), then you've only spent $325 more. That's a true savings of ~$175 on this trip, plus the savings on admission (and possibly resorts) on any other trips you might take within the year.
Keep in mind, though, AP rates are often room-only, meaning you can't add a dining package. (Atleast, they were the last time I crunched the number onf this, a while back. Not sure if it's changed.) That's something to think about if you were planning on using the Dining plan...the savings on the room might be outweighed by spending more on food, and/or losing the convenience of the dining plan.
If dining can be added to an AP reservation, you still need to get base tickets for everyone in your party. However, there's no rule that you *must* activate everyone's ticket (unless things have changed really recently); you could book everyone for the lowest base ticket for your reservation, and keep the AP holder's ticket for another visit. The tickets hold their value until they are activated (and then they are only good for 14 days, unless you buy the "no expiry) option.
I hope that helps. You should find more info about AP rates by searching for the topic in the search function -- there should be a FAQ about it, I'd think.