Thanks for your help, happy to answer any additional questions.

Or can additional names be included on the deed (joint tenancy) without negatively affecting the banks loan decision?

All additions are still in "roughed in" state, i.e studs, electrical runs, and plumbing runs, but no outlets or valves.  

She asked for a monthly $25 discount for paying 3 months-6 months in full in advance which I agreed to. 

If you are able to buy at a discount and want to get most or all of your cash out of the deal and use that same money on the next property without having to wait 6 months and are willing to pay higher points and fees for that flexibility then you may want to look into unconventional financing where there is no seasoning period.  

What is the likelihood of an accepted offer at that much of a discount?

I would need to have at least the 2% rule as a starting point, AND get it at a significant discount to appraised value. 

I realize the extra cashflow, and I can always make additional principal payments.  

Depending on which one you utilize they will not look at your "DTI" but they will look at your global cash flow in addition to the income and expense of the property.  

Should I just handwrite this into the "Additional Terms" section at the end of the agreement?