Top Epcot attractions with kids that age? They're all pretty cool, really. I understand your misgivings about the adult nature of Epcot, but WDW has gone far in making things kid-friendly.
To start, there is the Phinneas and Ferb (retooled Kim Possible). The Agent P game will be similar as guests become agents and use a high-tech secret agent device to search for clues. Different cases will be available in Mexico, France, Germany, Norway, Japan, China and the United Kingdom. (I got all that from another website). It's cool and kids will love it. Mine did when it was Kim Possible. We skipped it this last trip (Jan., 2012) because my 11 year old had done it before, but it's still a great time).
Club Cool is ALWAYS a hit with kids of all ages -- and adults too! This really isn't an attraction, more a showcase for Coca-Cola and it's products. There are some hands on areas where you can make your own souvenir bottle or build a cup (all for a price). But aside from that, you can sample many, many soft drinks from aroundt the world for free! Now, there will be some unchecked belching going on, that's for sure, but it's pretty cool to sample that stuff from other countries and cultures. And, as always, watch out for the Beverly from Italy.
As for rides, there are tons for your kids! You know all about Soarin and TT and Mission Space, but there's other stuff, too. A family favorite is Spaceship Earth. I know it's freaky, but I really, really, really LOVE the smell of Spaceship Earth. It's a greasy, earthy, moldy kind of funk that just triggers some great WDW memories for me. But I digress. I find that the imagination is really triggered when you are on SE and start going backward, looking up at all that "stars." It's a really cool effect and one kids love. Plus, there is some real education thrown in that kids won't even realize. Sneaky ol' WDW!
Living with the Land boat ride is slow and relaxing and a great way to take a break and cool off.
Turtle Talk is a favorite of all the kids all the time. Make sure your kids get up front and wear some Mickey and Minnie ears because Crush likes to talk to kids who wear their ears. That technology is pretty cool, incidentally. The interaction is in real time and your child is truly being spoken to by "Crush." It will blow them away.
Don't forget the Small World-type rides in Norway and Mexico, either! And for cryin' out loud, don't skip The Seas with Nemo because it's a really cool ride for kids (and me, too!).
Test Track, I can take it or leave it. Lately, I've left it because unless your kids are really into automobiles, there's not a whole lot a child is gonna get into. They can design cars in this expansionk but in the end, they are riding in a car, doing 60 around a test track. We rode it once, it was fun. Twice, it was okay. Third time, we were like

. That, of course, is one man's opinion. There are those who ADORE TT and will tell you it is the most awesome ride ever. Go figure.
I didn't realize how much I had written until I scrolled up just now. But let that be a sign to you that there is much to do for kids at EPCOT these days. Go, have fun. You likely will need two days to do it all, unless you are some sort of paramilitary enthusiast who hits the parks like Sgt. Fury. (To each his own, but that is not our style).