In the face of a high number of change requests, focusing on delivering incremental value through multiple smaller deliveries can help mitigate the risk of deliverable rejection. This approach, often associated with agile methodologies, allows for more frequent feedback and adjustment, reducing the likelihood of large-scale rejection at the end of the project. It also allows for changes to be incorporated more smoothly and continuously, without significantly disrupting the project timeline. References: PMBOKGuide - Sixth Edition, Section 6.7.3.1: Deliverable

To prevent delays due to noncompliance with environmental codes and bylaws, the project manager should have proactively mapped out all environmental compliance requirements at the start of the project. This includes identifying potential risks to achieving compliance and preparing mitigation strategies. By doing so, the project manager ensures that the project aligns with all relevant environmental regulations from the outset, reducing the likelihood of delays and ensuring the project contributes positively to environmental goals.
: (Based on the PMBOKGuide and standards from the Project Management Institute12, and the principles of environmental compliance and risk management as outlined in the Professional in Business Analysis materials34.)

According to the PMBOK Guide, the project manager should manage stakeholder expectations and communicate any changes that affect the project scope, schedule, cost, or quality. The project manager should also collaborate with the product owner, who is responsible for defining and prioritizing the product backlog, to ensure that the stakeholder's needs are met. The product owner can assess the value and urgency of the new requirement and decide whether it should be added to the current sprint or deferred to a later release. The other options are either too passive, too risky, or too disruptive for the project. References: PMBOK Guide,
6th edition, page 49-50, section 2.1.3; page 135-136, section 4.2.3.1; page 540-541, section 13.3.2.4.

The project manager should meet with the team member's functional manager to try to remove the impediment that is preventing the team member from completing their user story. The project manager should explain the impact of the delay on the project scope, schedule, and quality, and negotiate a solution that would allow the team member to resume their work on the user story as soon as possible. This approach is consistent with the agile principle of removing impediments and enabling self-organizing teams12. References: 1:
PMBOK Guide, 6th Edition, Chapter 5: Project Scope Management 2: Agile Practice Guide, Chapter 2: An Agile Mindset

In a scenario where a competitor is also working on a similar product, it is advantageous to use an incremental delivery approach. This approach allows the project team to release portions of the product to the users rapidly. By doing so, the project can gain a competitive edge by being first to market, and also receive early feedback that can be used to improve subsequent releases. This aligns with the PMBOK guide's emphasis on tailoring the project approach to the objectives and market conditions1. References: = PMI-PMP: Which delivery approach should the project manager use for business transformation1; PMBOK Guide2.