Most of what ended up on screen in seasons two and three about Kara is actually in the series bible
, dated December 17, 2003. It's an interesting read, and shows that a lot of thought went into the characters on the show (which is probably why the show was best when focusing on character drama, rather than plot theatrics).
That's a fascinating document that I've never seen before. I find it very interesting that, while some minor aspects were changed as the series developed, some of them held amazingly close to what actually happened later.
For example, there are scenes described in this 2003 series bible, before a single episode had been written, that we actually see dramatised in the series finale in 2009. Lee and Kara's first awkwardly flirtatious meeting, and the circumstances surrounding Roslin's family's deaths, turn out exactly as described in that document, despite however many changes and developments the entire show went through over the intervening years. That demonstrates a real vision for who these characters were back at the beginning, and a real commitment to keeping them that way by the end.
As for Starbuck, there were also Leoben's lines in "Flesh and Bone" in s1 where he talked about things he shouldn't have been able to know about - that Kara's mother believed that suffering promoted growth and therefore made sure Kara suffered.