Mind Your Follow-Through
Note that Defy Danger starts out with:
When you act despite an imminent threat or suffer a calamity
Getting rushed by screaming kobold fanatics who've set themselves on lightning* is pretty calamitous, and if you hit on a 10+, that's great! But what it means is that the threat doesn't come to bear right now, not that it vanishes forever - "defy" doesn't mean "eliminate".
Yes, you are encouraged to start setting up the scene with softer moves, but all of these moves are things that are actually happening in the fiction. The players aren't trying to, like, counter and eliminate your moves or anything, they're also taking actions in the fiction and accomplishing their own things. They can manage to be both momentarily safe and still very much in danger.
So, you hit on a 10+. The screaming kobold fanatics haven't gone away. It's just that when the first one rushes into the innocuous-looking jar/carefully positioned Leyden mine and they both go up in a cloud of electroclasm and smoke, you're not right there with them.
Awful lot of jars in here, aren't there?
* no one ever said the path of the blue dragon fanatic would be easy
Mind Your Setup
Tell them the requirements or consequences and then ask is often underestimated, but it's an excellent way to extend the results of moves without having to write entirely new ones.
So if, for example, Stringfellow surveys the upcoming holosparkst, decides it's time for the better part of valor, and says he's diving out the nearest doorway, that does sound like Defy Danger too, doesn't it? But you can always say:
Sure, but things in here are ramping up rapidly. If you make it out, getting back in to help everyone else won't be nearly as easy.
Or:
Sure, but whatever that just kicked off is already cascading around the exits. You'll be taking 1d6 damage through armor just to try.
Or even:
Sure, but, gosh, there's all this smoke in here and your ears are still ringing from the blast. You can get out somewhere safely, but it's not entirely clear to you where that's going to be.
And then end with:
Is that alright?
And if it's not, then Stringfellow isn't going to dive out the door in the first place. His turn in the spotlight will be spent doing something else. And if it is, then even a 10+ on a Defy Danger will still leave Stringfellow in a bad position. It doesn't violate the spirit of the move to do this - accepting those known bad outcomes is just the cost of making the move in the first place.
Mind Your Prep
And, of course, if you knew all along that there'd be kobolds in these ruins and they laid traps like the dickens, you can sit down and craft custom moves to deal with this and take Defy Danger off the table as an initial reaction. Something like:
When Lightning's Claw springs their ambush on you, say who was the most cautious among you and have them roll +WIS. On a 10+, they pick 1. On a 7-9, the GM also picks 1. On a 6-, all 3:
- You're right where they want you. Everyone takes -1 ongoing to all rolls to dodge or escape, until you're out.
- You didn't see this coming. Pick someone else in the party to take the brunt of the first attack; the GM will make a move against them.
- They timed this one perfectly. All their damage is best of 2 rolls, and when they gang up it adds +2 damage instead of +1.
But you don't need to haul something like that out all the time, just for when you want it to be a sufficiently big deal that a regular Defy Danger doesn't seem like it should be able to resolve things satisfyingly on its own.
Foreword
Remember that your job as GM is to follow your Agenda and Principles, even when doing behind the scenes stuff like this. So Fill their lives with adventure, ask questions and use the answers, make a move that follows, and draw maps, leave blanks are in play here, along with their unlisted friends.
Piecemeal
These kinds of questions can work, but are best answered one piece at a time. Think of it like the game Twenty Questions, where you don't know the answer yourself but each question narrows down the possibilities until only one remains.
How did a dozen goblins ransack an entire village? Let's play to find out. I'll skip everything but questions for brevity; this isn't an interrogation, and these questions should come up naturally from time to time.
GM: As you approach the village, you smell smoke. The last bend in the road reveals the burnt out village is still smouldering and is littered with corpses. Fighter, what kinds of wounds do they have?
Fighter: They don't have any defensive wounds; it looks like they just stood there while someone stabbed them.
GM: Ranger, you're the tracking expert. How many of them were there?
Ranger: There are footprints all over, but it looks like thirteen. One of them has a limp.
GM: Thief, as you scout, what oddity did you find?
Thief: The temple had some kind of brutal ritual performed recently. It's pretty grotesque.
GM: Cleric, what do you recognize about the symbols?
Cleric: Looks like the Goblin god of magic and death. Something about binding souls of the sacrifices in an exchange.
GM: Wizard, what magic do you sense nearby?
Wizard: I found two things; a wide area sleep spell and a powerful spell for opening some kind of arcane prison underground.
GM: Well, it looks like a dozen goblins were able to ransack a village of 1000 by putting the whole town to sleep magically, so they could perform this ritual. Do you think they'll do this again? Can our heroes stop them? Will the dead break free from their underground prison? Find out next week when our thrilling series continues!
Frame Challenge
Remember the plain English meaning of the word "stakes". There should be something clearly at risk, or an answer to those questions that significantly impacts the world (or our view of it). The dead might overrun the living. Knight Peregrine might die. Those are clear and compelling. They also invite more open ended questions like why can't Knight Peregrine be healed? and what is involved in the Ritual of the Souls?.
In my opinion, the issue with your Hard questions is there is no compelling aspect to it; they're more like supporting questions. Can we defend the remaining villages from the goblins begs the question of How did a dozen goblins ransack an entire village?. Can we secure Deeprock for the dwarves? depends quite a bit on What's inside the Cavern of the Deeprock that's chased all the Dwarves above ground?.
Best Answer
The point of Dungeon World published adventures is, like all published adventures, to take some of the burden of prep off of the GM. But in Dungeon World, prep is limited to detailing fronts and drawing maps with blanks (both literally and metaphorically). So published adventures in general just do some or all of that for you.
A good DW published product will give you some fronts, dangers, custom moves, and background context sketched in with enough detail for you and your players to riff of of, but with enough blanks - undefined spaces in the characters, the physical place, the wider world, etc. - for you to fill in with the ideas that are sparked at your table.
Without any prep, you are unable to use the Exploit your prep GM move. Whether the prep is your original work or published prep doesn't really make much difference.
For a free example of such published prep, I like I'm on a Boat!. It's got the bones described above - but leaves plenty for you and your table to flesh out.
Dungeon World is not just D&D with 2d6. It is not in the simulationist vein of many 80's and 90's systems. It takes a significant shift in your understanding to play properly - it is meant to be played as written. I suggest that you read the rulebook (especially the GM chapter) and the Dungeon World Guide again. Then come back here and read some of the DW questions and answers to see if you're building the correct impression of how to play.
I ran my first few Apocalypse-powered games wrong because I thought I knew what I was doing. The understanding will come.