Please click on the link below which explains the detailed steps on how to create a custom section in CREATE USER TABLE.
communities.bentley.com/.../9236.create-section-by-specifying-profile-points
Regarding your second point, I have already explained in my previous reply that as this is a non-standard section, so it's geometrical information is not considered by Staad and hence you can't see the sectional profile in Staad, which is why Stress value at different profile point of section could not be generated by Staad (as no profile points are generated in Staad).
For more detail, you may also follow the discussion in the following thread.
communities.bentley.com/.../271172
communities.bentley.com/.../9236.create-section-by-specifying-profile-points
Regarding your second point, I have already explained in my previous reply that as this is a non-standard section, so it's geometrical information is not considered by Staad and hence you can't see the sectional profile in Staad, which is why Stress value at different profile point of section could not be generated by Staad (as no profile points are generated in Staad).
For more detail, you may also follow the discussion in the following thread.
communities.bentley.com/.../271172