1. A5, but the pocket is very cool :) I just rarely play outside my home.
2 & 3. I think having the constraint of only 2-3 dice is better to be honest. I use d6s for d6 and Fate rolls, and d20 halved for d10s because I usually have them on hand.
4 & 5. Most: NPC behavior, quest, pay the price. Least: Dungeon generation, location, wilderness encounters (systems I play usually have their own, world-specific to roll on), and the icons.
6. I commented about it more extensively on the past on the main page; more tables about NPC actions and maybe something about magic.
7. I use it to supplement my solo runs :) I tend to try a lot of fantasy RPGs, and they introduce a fun level of variance. I guess I'd say shorter adventures -- some of them take days of play but they're no Odyssey.
8. Usually the most famous fan supplements of whatever I'm playing. I Juice whatever they're lacking.
9. I roll my dice physically, but everything else (keeping notes, drawing maps, the character sheet) is usually digital.