I have a borrower that did the loan application via our Mortgage Bot internet system and never set foot into the branch. on the loan application under the GMI it was left completely blank - he did not indicate any information. However, he borrower did fill out the DEMO information amendment. Should I use the information that was given by the borrower from the DEMO amendment only?

What is a DEMO information amendment?

Assuming you mean the Demographic Information Addendum, that's the only thing that should be marked. The GMI section (Section X) on the 1003 application form is suppossed to be marked out so that it cannot be completed.