The loners that they're talking about are younger siblings that decide to strike out on their own or old leaders after they step down. They'll live on the family territory, but apart from the others as hermits essentially. Their land isn't as ideal as the main families and tends to push them in greater contact with humans. These are the dragons that tend to show up in the classic stories.
re Onasaki:Only the second child becomes a a Drake. The younger ones could potentially try an overthrow, but If they did they would be facing both the eldest and their Drake, considerably worse odds (especially since dragons traditionally get more powerful with age). Usually these odds will discourage the youngest from ever trying.
re Zheyna: yup, looks like Drake's mom had a bit of trouble in her past.
re Neko with a Katana: ^_^
re Imola: heh, the line tool doesn't turn out so well for ruins.
Am I seeing twins?????? Actually, I was wondering....how are the dragons in your story born (eggs or like mammals)? And if like mammals, what happens if twins are born after the first child????