Unusual ways to find bugs quickly

Have informal chat with developers and try to find out
1. What are the functionalities/functional areas they are struggling to code?
2. What are the functionalities for which coding effort has been shared by more than one developer?
3. What are the last piece of functionalities they are stretching themselves to finish it off within the deadline?
4. What are the functionalities where the requirements are not that clear and developers are having more discussion with the product manager to know the expected behaviour to write the code accordingly?
5. What are the functionalities they have coded after coming back from the long vacation?
6. What are the functionalities which was assigned to Developer A and later transferred to Developer B with a short notice?
7. What are the functionalities coded by the developer who is actively looking for a job outside?
8. What are the functionalities coded by a developer who has already resigned?
9. What are the functionalities coded by a developer who is technically not very strong/disorganized in nature?
10. What are the functionalities coded by a developer who is not focused enough (who goes to have a cup of coffee, tea a number of times in a day / always on chat/ social networking sites)
11. What are the functionalities coded by the developer who is not very confident about his code and keeps asking the tester whether any bug has been found out in periodic basis?