There is no 'right way', but it really does help to work with the narrative and expand on the questions through roleplay and conversation. Just asking all the questions outright misses out on so much that can be expanded upon and authored into your Dungeon World.

Remember that sometimes to disclaim decision making and ask the players instead is a great way to move the story forward in a direction that intrigues the players and makes for the unexpected!

Nice one Tim!
Bargle is such a bad arse :)

Roy, you guys are really getting into the 'World engine now - loving the emergent narrative, so entertaining on my way to work, thanks so much!

Do you have a copy of DCCRPG? The spells in there easily port over and they RAWK for descriptions on a near hit or miss :)

Just see 'HP' as mistake potential during combat or physical adversity. Its a measure of tension in the antagonism. Once they are whittled away, our heroes (or their foes) cannot handle any more mistakes without facing death's dark gates. So use the deal damage move ALL the time - as a soft move, as a hard move, as a fictionally appropriate move in addition to whatever else is happening.

Don't forget that on a player miss you get to make as hard a move as you'd like (don't hold back now).

[tricks of the trade]

There are no 'opposed' tests in DW. Player's characters may aid or interfere, and they can Discern or Parley against each other, but NPCs are just narrative tools of the GM.

1) Is it interesting to the story to have the villiger spot the thief? Is the villiager a named NPC with a stake in the unfolding events? If no, just say Yes and roll with the fiction, no roll required. Otherwise its using tricks of the trade as written. Follow the options on a 7-9! Make as hard a move as you'd like (as GM) on a miss.

2) The thief should only make a Discern realities check if you think that the fiction is supporting that move. 'Do do it, do it', right?
Is the thief closely studying the situation or fey creature? Then sure, roll away. The answers they get will depend not only on the roll, but also what your prep demands. Be honest with the players. Maybe the fey creature will avoid deep appraisal, no matter what the roll.

So when the thief discerns realities on the fey creature when she offers them the jewel they've been coveting and rolls a 10+ and first asks the question: What should I be on the lookout for?

You don't have to tell them "The Fey is trying to lure you to your Doom" (which is a truthful answer), but instead: "This Fey is magically powerful and is using all her wiles to reassure you of your safety, She is likely trying to fool you."

As the conversation develops and the thief asks their other questions, be generous with the truth, the truth being that the fey is much more powerful than the thief and likely to fool them every time. Be expansive, its about the bigger picture.

[Replacing the options & moves for races]

What? Races for PC's? woah, that's cool. I'd just use Jonathan's advice from Dark heart of the dreamer...

Replacing the options & moves for races
When you create a new adventurer, decide on your species, ethnicity, and cultural heritage, choosing anything or any combination of things that sounds interesting to you and the other players.
For example, I might play a marsh-dwarf witch who has some spiderlord ancestry.
Then, pick 2-3 heritage moves to start with, selecting from the “monster moves” that best match your heritage. No matter where or whom you come from, in someone’s eyes, you and your family are monsters.
I pick the Dwarven Warrior move “Drive them back,” the Spiderlord move “Enmesh in webbing,” and invent a move based on the character’s training in wilderness survival, “Scavenge for food and medicinal plants.”
At the beginning of a session or when you invoke your rights of blood and tradition (however you do that), roll+Wis. On a 10+, hold 3. On a 7-9, hold 2. On a miss, you still hold 1. Spend this hold 1-for-1 during play to make a heritage move, just like that.

My favourite part was the Wheel of Justice which the hardholder rolled when someone was caught doing a severe crime.

'You know the rules in Barter Town! Break a deal, face the wheel'.

[discerning realities]

As the players start asking questions about the scene, suggest that they are discerning realities?... On a miss or soft hit, make the hard move that the pickpockets steal something (take away their stuff).

Great Idea!
First you need to get your players on board with your 'concept' since the answers they give to your provocative answers will shape the setting far more than your prep will.
If they are down with elemental clerics, cool! But then, does anyone want to play a cleric? If no, then all your ideas are just wonderful colour for the setting, if someone does want to play a cleric, Uzio gives great advice. I think a cleric / druid hybrid seems pretty on the money.

Gnome7's Barbarian :)
http://www.mediafire.com/view/?2ma41419ivubnzu

[discern]

oooh! Great adventure :)

You've read the chapter in the appendix on converting adventures right? The main thrust (as you've rightly surmised) is to retain your agenda, but be inspired by the situations, setting and dangers of the module. You are effectively focusing your options on a hard / soft move (and scene framing) to the prep at hand.

So have the wizard as presented! If he's the 'signature' monster of the adventure, what's his instinct? What does he want? Freedom, yes? So write a couple of impending dooms that will come to pass as the adventurers do nothing to change his situation - one of the most effective ways to do this (I've found) is to re-incorporate info revealed during chargen and bond-writing into these portents and/or have other factions in the dungeon interact with the wizard according to their instincts given the players actions.

You could even frontload the session as you start in a tense situation, write an Adventure move such as the one on p.352 and tie the results back to knowledge / leverage on the wizard.

Heck, why not just open the game THERE - in a tense situation with  the wizard, they have found him and he offers them something far more beguiling than just gold (look to their character sheets and bonds) to set him free. Combine this with an impending doom of another danger in the dungeon and you have time pressure added to the mix.

I mean this is ripe for getting the players to discern and spout lore, introducing new and exciting details to your dungeon world about the wizard and his history. All you come to the table with is that he is powerful, he is trapped by his own foolishness and that he wants out big-time.

In regards to your poison custom move... I like it! Not too harsh at all, it is poison after all... There was an old 'saving throw' move from an earlier edition you might like to resurrect / modify? How about:

Make a Saving Throw (Con)
When something inflicts an effect (magic, poison, calamity) upon you, roll+Con. On a 10+, nothing else bad happens.
On a 7-9 the GM chooses one.
On a 6- the GM chooses two.
• You drop something valuable
• You break something mundane
• You miss something important
• You lose your footing
• You lose track of someone or something
• It’s worse than it seemed—take 1d10 damage(ap)

Which really is just a 'softened' version of your move :)
I'd just add a few of the above choices to your iteration and write it up like so:

Make a Poison Saving Throw (Con)
When deadly poison inflicts its effect upon you, roll+Con.
On a 13+, you feel a shooting pain, but the venom has no other lasting effect.  
On a 10-12 the GM chooses one and you choose one.
On a 7-9 the GM chooses two and you choose one.
• You drop something valuable
• You break something mundane
• You miss something important
• You lose your footing
• You lose track of someone or something
• It’s worse than it seemed—take a debility

On a miss, Last Breath Sucker.

Don't forget there is a whole wealth of custom moves potential in the 13+ result... Each new advance or 'level' could unlock say 1, 2 or 3? existing moves at this superheroic level.
Use the AW advanced fuckery chapter and knock yourself out. This could apply to both basic and playbook moves.
For instance:
Hack 'n Slash: When you attack an enemy in melee, roll+Str. On a 13+ you deal your damage +1D6 to the enemy and avoid their attack. On your option you can deliver your maximum possible damage to your opponent but expose yourself to the enemy's attack. On a 10-12 you deal your damage to the enemy and avoid their attack. At your option, you may choose to do +1d6 damage but expose yourself to the enemy’s attack. On a 7–9, you deal your damage to the enemy and the enemy makes an attack against you.

Woo!
I'll review issue one if you like :)
Um, sorry I diidn't contribute to issue one for various real life fabric disturbances, but I have some ideas ready to roll for issue 2, thus my suggestion for the theme is 'Make Maps, Leave Blanks...' focusing on minimal prep gaming for Dungeon World.

Dan from the bookguy32 https://twitter.com/Thebookguy32 has done a few bespoke prints and binds...
Maybe he can shed some light?