Can I use pdf2cad to convert (scanned) raster drawings to CAD as well?
No. pdf2cad is not raster-to-vector software. It cannot bitmaps into editable lines, shapes and objects. Raster images in the PDF file are saved as separate TIFF or JPEG files and referenced in the DXF output. So when you open the DXF in AutoCAD, you will see the images show up as well. You can use them as backgrounds, for example.