Since we've exchange some e-mail, I know you're asking about this question from the GEDCOM FAQ: "What should you do if some people in your file don't have names?"
The general answer is there at http://www.wikitree.com/wiki/GEDCOM_FAQ#Unknowns but to answer your specific question: No, you don't need to skip people if you have a surname and birth date but no first name. If you had no birth date, then yes, you'd want to skip them. As long as they're some information in your GEDCOM it might be worth importing them. If it's nothing but a surname they should be skipped.
Thanks for wanting to do this right.