Sorry, I missed your reply!
The problem with barbed wire fences is that they might run full tilt into them and seriously injure themselves, so it's recommended not to use them to contain them.
You have to pen them. They're semi-nomadic in the wild and wander pretty far. If you let yours free range there's a good chance it will just go wandering off.
I wouldn't say bond as in become friends with them, but if raised with them they will tolerate poultry and not chase them, etc.
They kick and stomp things that they don't like - so small predators like foxes, raccoons, etc, are asking for death if they wander into an emu pen. They probably...
People do eat them, yes. For the most part, they are raised for their oil and meat. Mine though are pets and livestock guardians. They also now come in a couple different color morphs, which people keep to breed and sell. I myself have two blondes for this purpose.
Being so tame, he's definitely someone's pet. He probably got spooked and jumped the fence, or something happened to take the fencing down. That's happened to me before - luckily mine didn't wander off.
Hope you can find its owner! Someone is probably missing him.
Emus can be fed either ratite pellets, which you may be able to find at a feed store, or if you can't find those, they can eat a 50/50 mixture of chicken layer pellets and rabbit pellets.