1. They're right. Gold Bar ($2,000)
2. Jack Russell Terrier Book, Fireman's Hat, Expensive Things and remote control things.
3. No idea. Never even heard about the carts having special powers...
& To get the gold bar, you find it on walks.
Good Luck with finding one though. ;)
PS- I heard those rumors to. Some people say it's true, others don't.