"Repeal and replace" has been the rallying cry for Republicans since the Affordable Care Act was signed into law in 2010. But now that most of the law's provisions have taken effect, some health experts are pitching ways to improve it, rather than eliminate it. An ideologically diverse panel at the National Health Policy Conference Monday presented somewhat different lists of ideas to make the law work better. But they all agreed on one thing: The Affordable Care Act is too complicated. "We took the most complex health care system on God's green earth, and made it 10 times more complex," said Jon Kingsdale, the first head of the Massachusetts health exchange created under that state's forerunner to the ACA.