Request for information : what project management tools and techniques would you consider "bare essentials" ?

I'm updating the 2015 edition of my booklet. Among the tools and techniques below, which do you think are the bare essentials and which ones are just not:

Appendix 1 - Sale initiative: the elevator pitch
Appendix 2 - Treat conflict. 5 ways to deal with conflict.
Appendix 3 - Rebounding after a difficult interaction. Replay.
Appendix 4 - Communicating without violence. The non-violent communication .
Appendix 5 - Prepare a negotiation. The negotiation grid.
Appendix 6 - Structuring a report meeting. The plan of a report.
Appendix 7 - Ask about the progress of a deliverable. The questionnaire sent to the responsible person of the work package.
Appendix 8 - Summarize the initiative.
Appendix 9 - Plan and track a project. the OPPM.
Appendix 10 - Read to sharpen his tools : a bibliography.

And which should be inserted in the list of bare essential tools ( I want to keep to 10, no more) ?

the " Parking lot", aka the 3W ( Who , What , When), the list of current actions.
RACI, the matrix assignment of responsibilities.

Your contribution is much appreciated.