Some images will help. It's very rare for rke to work and both standard and RNG ke to fail, so include images of the mesh and flow.
All boundary conditions must be checked for a model. The turbulent values are less critical than velocity/pressure but still matter. If you mean the coefficients in the turbulence model panel I advise leaving those alone: they're exposed for a reason but only alter if you REALLY know why!
Cavitation is another level of modelling. Do you want to see cavitation or just imply it's happening?