As for the images portion. When creating/editing a style, this is at the top:

Quote
If you use any images within your css properties make sure you include the full url and the images reside within their own directory in the styles directory.
Example: https://www.ubbcentral.com/version7/styles/image/image.gif

The reason for this is so the full path is translated during the export process so it will work when imported.