Radiation-driven mass loss largely determines the life expectancy of massive stars. I will present our most recent mass-loss predictions for massive stars, which are obtained from Monte-Carlo multi-line radiative transfer calculations. I will show how these predictions are expected to change as a function of metallicity (and redshift!) and confront the results against data from the VLT FLAMES large programme of massive stars. Finally, I discuss some of the more intricate aspects of the physics of radiation-driven outflows, emphasizing the relevance for the rotational evolution of massive stars into the Luminous Blue Variable phase. This is shown to lead to some rather unexpected results... in particular for the progenitors of supernovae and gamma-ray bursts -- calling for some major paradigm shifts of even our most basic framework of massive star evolution.