Beginner's questions on quest mode

Hello all, I find the project of making a correct AI very interesting, so I decided to try Forge and see how you were doing.
Of course, I was immediately "sucked in" by the game, and I can't stop playing Quest mode.
I do have a couple questions, though and I couldn't find answers in any sticky thread or even recent thread.
1) Rules are enforced during the match, but absolutely not during game construction. My pool contained Laboratory Maniac, so I just tried to make a 9-cards deck, and it worked. After 20 games or so, I have a 7-card deck that always wins on turn 1 by playing Maniac and free-cycling a card. Is that normal ? It shouldn't be too hard to at least force a minimum of 40 cards in a deck.
2) Since I earned an insane amount of credits with that deck, I bought pretty much all the upgrades in the Bazaar. Some of them (I don't remember the name, sorry) say that they increase the frequency of "quest encounters", or "quest proposals", something like that. I have 20 wins, and I still haven't seen those quests. What are they ? Challenges have appeared, though, and that brings me to the next question.
3) I beat the 4 dungeons in the challenge (all except the blue one, which is perfect against my current deck
), and they're still here. Is that normal ? Can I just beat them indefinitely ? And what would that give me ?
Thank you, I know some of these questions must seem obvious, but the total absence of manual or FAQ kind of confuses me. ^^
Of course, I was immediately "sucked in" by the game, and I can't stop playing Quest mode.

I do have a couple questions, though and I couldn't find answers in any sticky thread or even recent thread.
1) Rules are enforced during the match, but absolutely not during game construction. My pool contained Laboratory Maniac, so I just tried to make a 9-cards deck, and it worked. After 20 games or so, I have a 7-card deck that always wins on turn 1 by playing Maniac and free-cycling a card. Is that normal ? It shouldn't be too hard to at least force a minimum of 40 cards in a deck.
2) Since I earned an insane amount of credits with that deck, I bought pretty much all the upgrades in the Bazaar. Some of them (I don't remember the name, sorry) say that they increase the frequency of "quest encounters", or "quest proposals", something like that. I have 20 wins, and I still haven't seen those quests. What are they ? Challenges have appeared, though, and that brings me to the next question.
3) I beat the 4 dungeons in the challenge (all except the blue one, which is perfect against my current deck

Thank you, I know some of these questions must seem obvious, but the total absence of manual or FAQ kind of confuses me. ^^