Some combination of the above. This is the category into which most family histories fall. One effective way to advance 4 to 5 is by using numbered or lettered appendices. All of the above, plus historical context. I add this here, but do not intend to elaborate on this form of family history, except to say that if this is the route you are considering than you need a whole other lecture, especially when it comes to seeking out a publisher.
Historical fiction is a valid form of family history writing.
So then, your first job as family historian is to decide just how far you want to go with your writing project. What you had for breakfast this morning is history. My grandfather started every day with a slab of fresh bread slathered with home-made butter and dripping with molasses kept in a barrel in the summer kitchen. He lived to nearly 90, so much for the cholesterol theories. In between your breakfast and the breakfast of your most distant ancestor are thousands of fascinating stories, facts and tidbits.