Using iTextSharp (and c#/ASP.NET) is it possible to open an RTF document, manipulate it by replacing some text, insert an image (WMF or PNG), and the export that manipulated
No it is not possible per se with iTextSharp. Better approach will be to use Word Object to open document, do mailmerge and then save those documents ad HTML. Now you can use iTextSharp to parse html and create PDF.