When a defect is first identified and logged, it is in the "Open" state. This means that the defect is now recognized and needs investigation or action. It has yet to undergo the various phases of the defect life cycle where its validity and resolution will be determined.

Incremental Integration Testing is a process where individual units or components of a software are integrated gradually to ensure that interface defects are detected and corrected. It helps in detecting issues that can arise during component interaction.

Adapting to changes in the application under test is a challenge as any modifications in the application's UI or functionality can break existing automated test scripts. This requires regular updates to scripts, making maintenance resource-intensive.

Auditing in Configuration Management ensures that the current design and build state of the software matches the latest product baseline. It involves a systematic examination of the processes, making certain that all procedures and standards are being followed, ensuring the integrity of the product.

Continuous Delivery focuses on ensuring that code changes can be deployed to production at any time, making the release process reliable. Continuous Deployment, on the other hand, ensures these changes are automatically deployed to production frequently without human intervention.

While Load Time, Response Time, and Throughput are common metrics used in performance testing to measure various aspects of the system's performance, "Number of Defects" is not a performance metric. It is typically associated with functional testing and bug tracking.

Error Guessing is a testing technique where testers rely on their past experiences and knowledge of system failures to identify potential defects. Instead of using a systematic approach, testers use their intuition to "guess" where defects might be present and construct tests based on these hunches, drawing from previous issues they have encountered.

Load testing focuses on understanding the behavior of the system under a specific load or request volume. Metrics like latency (response time) and throughput (number of requests processed per unit time) are crucial.

Usability Testing focuses on a user's experience with the application. It ensures that the product is easy to use and provides a good user experience. Issues like button placements, text alignment, and other design-related aspects that might hamper the user's experience or make the application difficult to navigate are typically identified in Usability Testing.

During Test Planning, the Test Plan is the key document that captures all aspects of testing, including the identification and assignment of roles and responsibilities, resources, schedules, and other relevant details to guide the testing efforts throughout the cycle.