My take on Starbuck - remember when they were talking about the 13th Cylon - the one Cavil boxed early on? He's her father. The reason he disappeared was because Cavil came and got him (and boxed him).
Yep, that's my guess too. 'Daniel' was her father, hence the Starbuck/Hera connection (they're both half-Cylon, half-Human). Ellen also described Daniel as being a gentle, artistic type, which fits with the way her father's been described. This could also help give Starbuck closure by explaining why her father 'disappeared'; perhaps he was killed by Cavil when he took out that line.