Moving the camera around: He's zoomed in through Sony Vegas, and walks around with Jimmy in FPV. If he runs around, he zooms in even further.
How he makes characters do what he wants: He provokes them to do so, like saying hi to them, insulting them, picking a fight with them, etc. all before recording.
How he spawns them in places they don't normally spawn: By editing Trigger.img. I spawn characters where I want through lua.