1. No. All twelve of the original expansions are still brought into print periodically, I think they're all on the store now or until they run out again.
2. Some of the pinups have small amounts of gameplay, but mostly not.
3. Neither yet. Apparently the expansion will have both, somehow.
4. Yes, we're still waiting on Wave 3 and 4 from the second Kickstarter.
5. No, you can proxy the survivor minis with whatever you want as long as you remember which is which in a given fight. Mix and match minis are just there for fun. EDIT: the box has both mix and match and multiple fixed-pose survivor minis.
6 and above: Haven't actually played yet, can't help.
The minis are highly configurable, so you can mix and match pretty much anything you want. The game comes with enough minis to build every armor set, but not every armor/weapon combination possible. For that, you will need to magnetize arms/wrists so you wan swap weapons. Some people even magnetize the whole thing so they can compose torsos, heads, arms...
Both of those are expansions from the current, second Kickstarter, that will hopefully ship sometime in 2019. Advance comes in two parts -- more complex rules for the base game, and a book of alternate campaign timelines plus rules upgrades for the original twelve expansions.
The "dungeon crawl" is the Nightmare Ram expansion, which involves fighting your way through a dungeon to g et to the Ram.
There’s also long been rumours of a follow-up game, tentatively titled Kingdom Death: Labyrinth, which Poots was sort of kind of planning to eventually get to years ago, which was rumoured at the time to be a sort of dungeon crawl focused on individual mighty heroes versus some of the larger monsters of the setting, and which we’ve heard nothing about for years and which maybe he’ll announce a Kickstarter for tomorrow (or more likely next Black Friday) or which we might never hear anything about again because it’s been years, it was never formally announced, and plans change.