Quark is still slightly behind InDesign in that you cannot embed a CMS profile in your PDF. So, you need to have everything figured out beforehand.
Prior to exporting a file as a PDF, choose Utilities > Usage. Check that the fonts showing are the ones you actually used and that the images are all linked correctly. If not, the resulting PDF might be in trouble. If a picture is listed as “missing,” it means Quark cannot find it in the location from which it was originally linked. You will need to update the connection using the Update button. If a font appears that you did not expect, click on Show First to find out where it first appears.
It is not uncommon for Quark and InDesign files to include line spaces that are specified ...