I am traveling ATW backpacking, volunteering, etc. and have a buddy pass that I'd like to make the most of. I've used quite a few Delta buddy passes in the past so I'm familiar with most of the ins and outs - I know that I can use it open-jaw, and must fly Delta flight + Delta equipment, but I have a couple of more complex questions:

1) Can I do something like JFK> MXP and FCO>ATL? Or do I have to return to the same airport I started from?

2) If I have to return to the same airport does my starting airport have to be in the US?

3) Are layover cities allowed? IE: JFK>CDG (a day or two?) and then onto FCO?

Lastly, did I hear that the pass system changed recently (in the last 6 months)? If so, how?

Thanks for any help you can give! Happy travels!