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.

The "Test Plan" is a comprehensive document that outlines the scope, approach, resources, and schedule of testing activities. It serves as a blueprint for all testing processes and activities, ensuring that every aspect of the testing process is covered and understood by all stakeholders.

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.

Enforcing a strong password policy would be the primary recommendation, as it directly addresses the core issue of weak passwords. This policy would mandate criteria like password length, complexity, and change frequency. While MFA and regular audits are beneficial, addressing the root cause is essential.

White-box testing is focused on the internal structures of an application. While Cyclomatic Complexity, Statement Coverage, and Path Testing are white-box techniques, Usability Testing is a type of black-box testing, focusing on user experience.

In the STLC, a Risk Management Plan provides a structured approach to identify, assess, and prioritize risks associated with the testing process. It offers a framework for making decisions and allocating resources based on potential impacts and likelihood of risks.