There are a couple of different options for the jib sheet.
You can lead it though a swivel cleat mounted on the crossbar (not shown in the diagrams - which answers your second question). Or you can have a combined traveller/cleat (like the photo right next to the diagram).
Which way you do it is up to you. I've had both systems and they work about the same. The only difference is you get a consistent sheet angle with the fixed cleat.
As for the traveller cleats, I think the swivel cleats are total overkill. They're heavy, they're expensive, they get in the way and they don't get used a whole lot. Lance cleats or small, fixed cam cleats are the way to go.