I'm wondering why there is no option to use non-uniform forces/pressures in 2D axisymmetric. I understand they could only be in one direction (along axis of symmetry), but it would be hugely helpful for hydrostatic loading cases (cylindrical tanks)... Is there a work-around for this? I've tried a 1-deg solid revolution, but the circular symmetry fixture doesn't seem to apply properly (pulls away from the very center along rotation axis, and doesn't seem to capture hoop stress correctly).

This is currently a limitation that I found in the SolidWorks KB. (Customerportal.solidworks.com > KB)

Add nonuniform load for 2D Simplification Studies.

The only workaround I can think of is adding split line and adding a "discrete" non uniform load or using a quarter/half of the model with the appropriate conditions. From your description, it sounds like you might not have the right symmetry conditions applied. It should work the way you describe.