Ah, didn't realize you were able to take advantage of the disability waiver.
1. Unless you have bad credit or the DtoI exceeds your ability to buy, you CAN be on the mortgage as a co-borrower even if you weren't a vet.
2. If you are not on the mortgage proper, the mortgage underwriter will NOT allow your name to show on the property deed. It clouds their First Right of Refusal privilege.
3. If something happens to your GF and both the mortgage and the house are soleley in her name, you're homeless unless she has specifically deeded the property to you as part of her will. That, or you and she make some kind of up-front legal provisions for shared ownership of equity.
4. If your GF dies and the mortgage is in her name only then you will have to qualify to either A) assume the current mortgage balance if there is an assumability provision in the mortgage, or B) qualify for a new mortgage. If you are a co-borrower then the transition would be seamless. She would be listed as a decedent and you, as the remaining mortgage holder, would become solely responsible for the remainder of the unpaid balance.
What you guys need to do is see a good estate attorney. Pronto.
That, or get married...
Brad