Responding to a few questions here:
Attorneys aren't "assigned" questions; it's generally not that formalized. The hiring committee just wants each of them to form an opinion about whether they want to hire you, and they ask questions that help them decide just that.
I wouldn't fly out on a Friday or saturday for a monday interview. It probably wouldn't hurt your chances, but it might. If you want to show an interest in the city, do it on your own dime. The only time I'd spend an extra day at the hotel is if you have an afternoon callback, which is kind of rare. This isn't to say that you can't schedule multiple interviews over the course of one trip; absolutely do that. It's expected an appreciated. Also, schedule those interviews on different days. Then you can have some time to hang out, and you're not rushed.
All travel expenses incurred over the course of callbacks are covered. Parking at the airport, room service, subway fare, etc. Your receipts probably aren't scrutinized too much, but use discretion. A $50 dinner is fine, a $200 bottle of wine with dinner is not.