disney experts come in - more questions

We may be planning a last minute trip to Disney World next week. We will be visiting family in GA and then driving down to Disney for a couple of days.
I read that children 2 and under are free, is this true? Do you need any documentation to prove age?
How is the weather this time of year? Any parks to skip because of the weather?
What about SeaWorld? Is it too much for an almost 3 year old?

ETA: any place to get discounted tickets?
If you get to the park later in the day, after 5 or 6 pm is it still a full price ticket?

Thanks.

Message edited 2/8/2015 4:50:38 PM.

Re: disney experts come in

Children under 3 are free. No proof necessary, it on your honor. I did bring a copy of my kids's birth cert just bc I didn't want a headache. They might ask your child how old they are, but we were never questioned. (We went one year when my younger one turned 1and my older one was one month from her 3rd birthday.

Weather can be very unpredictable. Make sure you have at least one hat and a pair of gloves with your winter coats. We went the first week in January and days were mostly upper 60's and low 70s, with one day about 80. But nights were anywhere from 40s and 50s. One night it was in the 30s and we had to buy gloves bc we were freezing. But the warmer day we got to swim. Layers are very important. When I was little we went in March one year and it was freezing winter costs every day.