Questions/ Questionnaire Templates/ Questionnaires

Hello,

While the steps to be followed regarding the creation of questionnaires are quite simple and intuitive, I do have some topics that are not that clear, therefore, I need the help of this Community.

1. What is the difference between Questionnaire Templates and Questionnaires?
2. If there is a need to modify the questionnaire (by adding/ removing questions, by adjusting some questions), which task has to be used: Questionnaire Templates or Questionnaires?
3. If the questions/ questionnaire templates/ questionnaires are created with an Owner and the Privacy is set to Public, can anyone with the right permission modify them later? Or is there a way to create these without an Owner?
4. What are the best practices for modifying a question/ questionnaire template/ questionnaire? What is the difference between Create a new version vs Update existing version?
5. Once a question is modified, in the question library, does it get modified automatically in the templates and the questionnaires it is included in?
6. When there is an adjustment, what happens to the questionnaires already answered vs the ones assigned, but not answered yet, or where answering is in progress?
7. If there are changes, can we report on the answers registered before the adjustments?

Thank you.