This right here is why you folks have the best e-payment system out there - nobody else responds in such detail.
That's fine - I can do without the pdf stamping for my purposes.
Just to clarify though, is this correct:
1) I can set a 1 year expiration on the download links sent out
2) During that year, the customer downloads a few times, he or she WILL get the updated pdf file
3) This will work with bundles (i.e., one purchase but customer gets 2 download links for 2 different files, no zipping. In other words, this is for a "buy this pdf and get a free that" pdf)
4) This won't work with pdf stamping (fine with me).