It sounds like you have a fabulous trip planned Matthew, I'm not sure if I can help you with all your questions in my limited space so please ask again if you have any follow up questions. Firstly congratulations on your wedding, I've never been to a Disney wedding but recommend you look at
THIS LINK which is the frequently asked question page on the wedding website.
Now dining I can help with, bookings from the UK can be made via the normal dining number 001-407-939-3463 this will incur International charges though so I often use this number 08448-610-610 and when prompted dial the US number. This then only costs 1p per minute, subject to change. I would also recommend you call at 12 noon GMT at exactly 90 days before your arrival for the best chance of securing reservations. I would recommend Crystal Palace with Pooh and friends or Garden Grill with Mickey, Pluto, Chip & Dale for your family but all the character dining is fabulous.
The park hours for May 2010 should be released around the beginning of February, I personally don't go to parks with extra magic hours as we've always found them to be busy. My main advice for structuring your days is to get to the park at opening, head straight to the main attractions for example in Magic Kingdom you should go straight to Fantasyland and ride Dumbo followed by Peter Pan etc. Your daughter will I'm sure also love to visit the characters in Toontown so do this early too to avoid long queues. I would then recommend you return to your hotel for a swim and nap. As you're there for 14 days don't try and do too much, have some rest days.
I would definitely check out
THIS LINK as there is some great information for travelling with little ones, there is also a link about baby sitting services too. I hope you have a magical trip!