Please be more specific on what the issue is. You want to add headers and footers in the already converted PDF or in the original file before conversion?
When you are printing from Excel please select print entire workbook and each sheet will be converted to its own PDF file. You do not need to select any certain sheets unless you specifically need those worksheets converted.
Please send us that specific document if possible along with this information so we can make some tests at email@example.com
Also mention the exact OS version and doPDF version you have used when printing so we can replicate the test environment as well.
Unfortunately doPDF is not intended or optimized for re-converting PDF files so this is why you are getting these issues with the fonts and the drawing. The quality of the PDF drops when this sort of conversion is done.
Thank you for understanding.