At buffets, your kids will have all of the same choices as adults, and can eat as much as they want. Boma was fabulous, and so was the breakfast buffet at the Crystal Palace.
As for other places, you just have to look around. PT 50's serves grilled fish, hot dogs, meatloaf, soup and salad. Mama Melrose's has grilled fish, pizza and pasta, fruit salad, and sundaes. Sci Fi has burgers and hot dogs. And that's just TS at MGM.
If you are looking for good kid's choices for CS, look at Epcot. Kids can order quesadillas, BBQ chicken drumstick, teriyaki chicken with rice and veggies, hamburger or pizza (the last two in Morocco, of all places!)
A lot of it is attitude. If you go into it thinking, "All of the kids' menus stink, they are all the same, my kids will be bored, my kids will hate it," then you are probably right.

You will set up that expectation for yourself and your children. If you go into it thinking it will be fun to try new things, and see what different places serve, your kids may feel the same way. And if you are on the DDP, a lot of people feel the adult meals are just too much food, so share a little with your kids, and they will be fine. And they will each have a snack credit every day for an extra treat
