I got two games in with some friends last night and we spent some time on these questions too. We interpreted it as the following:
1. When you finish off a group of mobs (say 3 Bats) or they are driven off, you discard their Encounter Card, draw a new one and place it face down (!) where the Bat card was - lets say this is hostile group 2. When hostile group 2 is activated the next time, you turn the new Encounter Card face up, and mobs listed on that card spawn from the Lychgate furthest from the players.
2. No, see "aftermatch": Inspiration is meant to be used during the game and is not carried over.
3. That's how we played it atleast, essentially there should be only one place where the dropship can pick you up right? In our first game we were literally being chased into the dropzone with zombies and skeletons hot on our heels!
We played two Hunt missions to keep it simple (two players were pretty new to the Warhammer hobby in general) but had tons of fun. Things can seem like smooth sailing while you're swatting bats, but then a Kosargi spawns while Brutogg is on the other side of the map and those distant Ulfenwatch suddenly Danse Macabre right into your face. And then Brutogg gets buried over there. ******!