Answering your questions:
1) As I had said, I'm using "the drop-down menu (right click on a file) to convert a JPEG file into PDF". So I'm not using any particular application; only Windows 8.1 and PDF Creator.
2) I haven't tried "setting the option to portrait or landscape manually", because if I set it to portrait, then I will have to rotate the final PDF if the original image was landscape (and vice-versa); or then I will have to change this setting (portrait/landscape) every time I have a file in a different orientation, which will be annoying (and extra work) as well.
Therefore, in my opinion it still seems that the best solution is pdfforge creating a "NO ROTATION" setting, so that the application will never rotate files when converting to PDF; as a consequence, the PDFs will always have the same orientation as the original files. That means no problem and no extra work for us, users.