I agree with the others. Get to DL 1/2 hour before scheduled opening, work the FastPasses, and hop over to DCA once DL gets very busy. If you go back to your hotel midday from DCA, you can take the GC entrance across from Grizzly River Rapids. From DL, you can take the Monorail from Tomorrowland to DTD to cut down your walk back to the PPH, but the lines get long for the Monorail at night after parades, fireworks, etc.
You'll enjoy riding the same DL rides that you enjoy at WDW. Some are almost identical and some are quite a bit different. It's fun to compare them But you're more likely to want to reride those rides that are unique to DL, so you might want to put those near the top of your list for the first day. Definitely do Indiana Jones early (perhaps grab a FP for it right off the bat). Yes, it's just like Dinosaur if you close your eyes and wear super earplugs, but the visuals and audio make it quite unique and special. The Matterhorn is another must do unique to DL, but it doesn't take FP. The line on the Tomorrowland side is usually shorter because most people come from the other direction. Many of the rides at DCA are unique. As pointed out by another poster, it's easy to hop back and forth since the parts are directly across from one another.
If you have an EE, you may find you can do most of the Fantasyland rides during EE; your kids are old enough that you may not need a lot more time than that for EE.
Possible first day plan, if not an EE -- Get in quickly, grab a FP to Indiana on the way over to Splash. Ride Splash, followed by Thunder Mountain, and Matterhorn. By then, you might be able to pick up a FP for Buzz; if not, hit another ride or two in FL, perhaps Storybook Canal and then pick up the Buzz FP before going to Indiana. Check out the Info Board on the way over to Indiana to plan what's to follow -- perhaps Pirates and Haunted Mansion before the Buzz FP and/or over to DCA. At DCA, grab a FP for Soaring and GRR (not linked), then go over to Screaming and hit a couple more Paradise Pier rides before riding Soaring and GGR. By then you may be ready for a nice lunch and swim break. Come back later for shows and evening entertainment.
The DL Information Board showing queue times for most of the more popular rides is located at the end of Main Street near the entrance to Adventureland. There should also be an info board in DCA near Sunshine Plaze.
My 14 year old DS has just about grown out of character meals, but he still loves Goofy's Kitchen. I like to schedule 1 PS meal a day, but I rarey make it a breakfast during the busy season, because I think the morning hours should be spent riding the rides.
You'll enjoy DL. The weather should be pretty mild compared to Florida. You might need a light sweatshirt for the evenings but you shouldn't need a rain poncho.
