Hey!
I can see you have lots of questions. I'd love to hopefully answer all of them - so here goes!
Yes, the quests ARE adaptive based on ability estimate on the past 50 questions played on Grockit, including the questions in the quest. The questions in the quest primarily function as targeted adaptive practice.
You're most likely not seeing a third quest because of your strong performance in the sections, and our model does not have enough un-depleted practice questions that match your ability level. We are in the process of adding more 'difficult' level questions, so your quests should re-appear when we add more.
There are a few ways to get feedback on your weaknesses. First, check out your analytics section in your profile. Here you will see a running list of every question type you've played in the game. This will tell you how many questions within each question type you answered, the average time you took to answer the questions and percentage correct. You can also see custom reviews of questions played by selecting the question types on your profile page and then click on select skills to review.
Another great way to study is to create custom games. You can access this from the lobby page. Click on create a game (left side of page), pick a section, then click on customize where you can choose the types of questions to review and difficulty level.
Hope this info helps!

Crystal