When I import a flat panel with a rounded edge as a vector import it does not record the rounded edge.

2D vectors cannot record something from a 3D image, either use the 3D component import function, or approximate the desired curvature of your edge using a Profile tool path combined with a Roundover Toolbit.

As long as your material and toolbit settings are accurate to your equipment, the Toolpath Preview will accurately show you the final effect as long as there is no requirement for an undercut.

Undercuts cannot be viewed in Aspire or VCarve Pro.