I am also serving in the Air Force Reserves 13 yrs AF now. (10 yrs prior service Army) looking to retire early in 2018.

I will never be one who lives with nothing and saves eveything however I do live a comfortable life and now will be acquiring buy and holds to help make it easier especially closer to retirement age. 

However since she has 5 years until retirement this is what she is asking 25k when we agree to the deal .The house needs Furnace , Hot water heater , interior and exterior Painting ,additional insulation in the attic .septic tank pumped out .

Is it still possible even if I am not a retired veteran?

You probably know someone with a retirement account that they may be willing to tap if you secure them with a mortgage. 

And they really don't like to see people lose money in their IRA's I bet that's much of it.. non experienced folks lending retirement money then losing it.. fed can follow via tax returns

I was told he wants to retire so I'm guessing maybe this structure benefits him tax wise.Is there a good resource I can use to read up on seller financing?

For example, I bought a property from a retired soldier that left the area and her management company had been trying to rent for 6 months.

You can transfer your retirement funds to a Rollover as Business Startup (ROBS 401k/PSP) in fund a real-estate operating company.

Half of those folks are in the labor force (others are retired, kids, college students, stay at home parents).