A few comments:
1. Don't use copy and paste. You should be able to add a PDF directly onto a layout using Insert –> Picture.
2. The problem with converting a PDF to a graphic is that you lose the PDF's inherent clarity—text is converted to pixels and will look fuzzy.
3. To get a PDF or any image to look clear in print it needs to be a suitably high resolution in the first place, and you pay for that in file size, so use sparingly.
4. You could experiment with storing the PDF form in a container field using FM's External storage. Then you only need the field on your layout, not the graphic itself. You might have to play around a bit with settings to get a printable result.
5. I can't comment on the Mac/Windows difference, but that is probably coming from outside FM.
You can drop your pdf in Filemaker.
In Acrobat Reader on your windows machine change the settings in "Advanced print setup" and then select "print as image"