character in the miniseries other than Adama could have died, and some did. That's the same level of threat you get with most sci-fi shows.
It's true you could do a more unusual and elaborate prequel series for Battlestar Galactica, whose protagonists have unknown endpoints - but then, that was basically Caprica
(Willie Adama was not just a fakeout, he was also a minor character). B&C wanted to put the focus back on Adama's career and the battlestars, which is fair enough.