Organizing additional OG types and relationships

Hello, I am struggling a bit to figure out the best way to organize a site with DC - hoping to get some pointers.

My current use case is a private site for my rather large extended family. I am thinking of a OG content type 'Family' and using subgroups for content and access propegation but perhaps OG membership and what not can be based off of user_relationships or noderelationshps rather than with og_subgroup?.

I also want to use the site for family history and would like to have ancestors as nodes. I like having OG for ancestors, because some of the research and for each individual will be somewhat a collaborative project. But then I can not use user_relationships ... so I end up with two systems defining people relationships? Maybe everyone should be an OG and I only use noderelationships. What would be the disadvantage of noderelationships vs user_relationships for users on DC?

Can someone post a list of items to address when adding an OG content type and adding relationships? Such as views, panels, and user create options?

Any suggestions and insights are invited.

thanks, tom

PS i have a sim post at d.o http://drupal.org/node/1202908