Basically, information received by their agents via a landline phone or fax, from a sister office or friend.

Most military families choose to live in the city of the base they will be working on. 

Zillow gave me a rental estimate which is based on 2-beds and rentometer did not include data for 1-beds since it was searching within 1-mile radius.Is it a good thing or a bad thing if there are no 1-bed 1-bath in the vicinity?

It's great that you found a seller willing to accept seller financing now just cover your bases.

Focusing only on traveling nurses is limiting the client base.

Based on what you have said above, I would recommend the Multifamily Bootcamp. 

But every other month we are at about $2000-3000 surplus.If we stay or buy a second home and rent 1st, the difference is about $1000 in our pockets.I don't want to make an untimely decision on buying home by missing some kind of interest rate change, based on short term financial struggles when 10's of 1000's of $$$'s could be made.

To experienced investors, I'm a RN based in Fishers, spent the last two years traveling.  

Now its just not answering your phone issues.. bottom line you need sales skills  Tech skills and its a life style not a job.

A good realtor (which is sometimes hard to find) is a great resource to estimate current property value and ARV, however, remember that they are going to give their opinion based on what they see on the market.