If cross sections are shown in the model, they are not shown in the STL file.
The STL file always uses meters for the unit of measure. All measurements from the original file are converted into the equivalent value in meters in the STL file.
To save a file that you received from another user as an STL file, the sender must have set the option to give you permission. See eDrawings Save Options and Creating eDrawings Files Using SOLIDWORKS Save As.
To save files as STL files: