A1: unfortuately we cannot diagnose the issue with limited information and the forum policy. I would suggest that you use an oline example and compare the results.
A2: the mesh is defined in this
discretization = linspace(-a/2,a/2,51); # z locations where fields will be calculated
https://optics.ansys.com/hc/en-us/articles/4414567929235-rcwa-Script-command
A3: once you run the script, the objects are shown with FDTD object where you can see the structures as usual.
A4: If you want to check the absorption inside the structure, please monitor the ix website as such featue is requested previously. If it is published you can vote. Or you can file it again.
Vote new features, and file your feature request
A5. You are right that traditionally it is not easy to simulate metals using RCWA. We encourage customers to try the new RCWA and see what difficulties or challenges you face and we'd like to help you. Please write a new post for this.
You are navigating away from the AIS Discovery experience