I would encourage a deeper reading into the PMBOK guide for the sections cited. Please double-check my answers.
#2: Verified deliverables are an output of the control quality process and are done by the project team. "The verified deliverables obtained from the Control Quality process are reviewed with the customer or sponsor to ensure they are completed satisfactorily and have received formal acceptance of the deliverables by the customer or sponsor." (PMBOK, 164). How do we accomplish this? Through an inspection or walkthrough with the customer. The deliverables, once approved, go from verified to accepted. This is done in Validate Scope.
#3: Yes, one output of the Close Procurement Process are closed procurements. "Confirming the delivery and formal acceptance of deliverables by the customer" (PMBOK, 123) is done in closing.
#4: The PMBOK guide is not a checklist, but rather presents standards and foundations for project management. Thus, the PMBOK guide does not specify what would be the final step as each project is different. PMBOK, 125 "Meetings are used to confirm that the deliverables have been accepted, to validate that the exit criteria have been met, to formalize the completion of the contracts, to evaluate the satisfaction of the stakeholders, to gather lessons learned, to transfer knowledge and information from the project, and to celebrate success. Attendees may include project team members and other stakeholders involved in or affected by the project. Meetings may be face-to-face, virtual, formal, or informal. Types of meetings include but are not limited to close-out reporting meetings, customer wrap-up meetings, lessons learned meetings, and celebration meetings."
If you were to ask me, the final thing to be done on a project, after everything is said and done, is updating the lessons learned registry and archiving all project documents. Concerning your specific question, if these were the only two question on an exam question, I would probably pick "measure stakeholder satisfaction" over "Reassigning personnel" just because the team should probably have already been released at this point or once the transition is complete, they are no longer needed, but again this is a tailoring question.
#5: This is why a project manager would carry out the Plan Communications Management process. There is no "best" way.
#6: It depends upon the contract and what type of termination it is? Is it for cause, convenience, or force majeure? Regardless, you would follow the termination clause in the contract. If it's force majeure (act of God), you may have completed a full order of 1000 flower pots for a customer and your plant burned down. You are now out of business. What could you handover to the customer? Nothing. Again, the PMBOK is not a checklist, but rather a standardized way to approach PM. You'll need to review the contract with the customer and NEGOTIATE first, then do some sort of ADR if a resolution cannot be achieved. One interesting note about early project termination is that a project manager does not have the authority to close a project. Rather, the PM should REQUEST project closure through the project sponsor.