To clarify my intention:
I'm going to try to pair dwarves up, where appropriate, so that they grow in relationships with one another and get married. (That may involve locking them in a party room. We'll see.) I find that normally my dwarves have a deity and about thirty passing acquaintances. (I keep them busy.)
When dwarves get married, I'm going to use Dwarf Companion to change their last names to be the same (I'll probably just choose between the man's and the woman's based on which one sounds better- Blazecastles over Bootconvent). Any children will also have the parents' last name. If a child dwarf earns themselves an extended name, I will consider taking the random extra elements added to that child's name and making it into a new last name (and a more appropriate honorific). So, Atir Blazecastles the East Recreation of Manors might become Atir Eastmanors the Quick Blade. This'll keep all the names from converging.
I'll probably use Dwarf Manager to enable some task for fortress children- basically giving them a chance at a specialty, like the adults. That way, the amount of time that they're a pure burden on society is only one year, but they still can't reproduce for 12. That sounds like a good compromise.
However, with 7 dwarves and no immigration, I'll just have too few genetic stocks (not that it'd actually be a problem in DF, but it is in my mind). So that's why I was thinking that starting with 12-20 dwarves would be good.
But I think that cheating takes the fun out of the game, so I want something fairly balanced. Which is why I ask:
How much is an extra peasant -worth-?