The astrophysical origins of the heaviest elements via rapid neutron capture remain unresolved, even with exciting recent progress in gravitational wave and astronomical observations. One key barrier to elucidating r-process origins using these new observables are the uncertainties that arise from the unknown properties of the thousands of nuclear species that participate in the r process. Here we consider the role played by nuclear physics uncertainties in our interpretations of r-process observables such as light curves, abundance patterns, and isotopic ratios. We will discuss the prospects for reducing these uncertainties via advances in nuclear theory and experiment and point out potential observables that may rise above current uncertainties.