Just as a reference point, the FAO store at Forum Shoppes has closed. Was very sad to see it all closed off.
When going to Bellagio to see the fountains, make sure you visit the Conseratory inside & stop back behind that to see the world's largest chocolate fountain.
I believe Ethel M Chocolates still gives factory tours & free samples, but not sure if there is a minimum age requirement or not.
Hard Rock has a new restaurant on the strip between MGM & Planet Hollywood. Depending on age, having a meal there & viewing the memorabilia they always have on display at HR's would be entertaining.
The light show overhead at Fremont Street only lasts a few minutes & only runs on the hour so don't know if it would be worth going down for. However you could pop into Mermaids & buy them deep fried twinkies for a treat or deep fried oreos & sit out on the street & coat yourself in powdered sugar, lol. They often have other live entertainment (music, stage shows etc) outside also - probably more on weekends than on weeknights.
There is a balloon lift ride same as they have at DTD on south end of strip now, but it is higher $ than Disney's is.
I have seen kids in every hotel in Vegas - not every one caters to children but they sure all accomodate them. You just have to keep them away from the gaming floor unless you are moving straight thru to your destination.