1. You can't send Shauna Kelly comments. She is no longer among the living. That page, though, is the best set of instructions on setting up outline numbering in Word available, anywhere, that I know of. The first few times doing it can be tedious; follow all of the steps.
2. To properly set up the numbering, you must set up all levels that will ever be used at the same time.
3. While using built-in heading styles is not required, it can make things easier.
4. If you are copying the styles to a different document/template, you must copy all involved styles at the same time. I use the Organizer for this. When doing so, I copy them all three times to maintain the relationships between the styles.
5. If you are having trouble copying them within the same document, you've done something wrong in setting them up.

You are welcome to read my chapter on numbering, but you should know that when I have to set up numbering that will survive editing, I go to Shauna's instructions every time. Numbering in Microsoft Word



You may want to take a look at A Global StyleSheet in Microsoft Word? This describes how to set up a template that holds such styles as a global template that lets you copy them into any document or template using a keyboard shortcut and macro.