I'm OK with the notion that the Earth we saw on BSG is the one we live on, just in the future... and not, as it turns out, where they really need to be going. Really, what are they going to do? Settle down on that radioactive dump? Not likely. They'll get what clues they need and move on.
The FrankenStarbuck thing sounds creepy and interesting. I actually think I've heard that very idea elsewhere--that Starbuck would find her own body, and destroy it to prevent anyone from finding out the truth.