But I cannot prove it.Now the plumber is demanding payment after we spent 15k repairing water damage and vacating tenants. 

My suggestion is to study the material and use the study exams to help you put it together.

But I don't need to prove that to you.   

I ran free classes that only required people to learn the basic skills by meeting once a week for about 3 months. 95% of the students failed to study.

If you are obtaining bank financing, the bank will more than likely want an environmental study performed, these studies can cost $1000's of dollars depending on what is discovered on the property.Is there a need for this type of property in the community?

But if your 6% proves to be too low, it'll be tough to make your projections.

Although i believe if you're completely new and plan on contracting out most of the work, its more important to study the areas, network and vet your people than to worry about the WHERE - theres certainly upsides for focussing solely on markets outside your own, its certainly doable and a lot of people do it, even (or maybe especially) when your starting out, the added risk can be minimized and downsides you cant eliminate may be worth the upsides.

I just visited the city to study the neighborhoods and view some properties.

I knew this flip was a good deal just from spending so much time studying my market before I decided to jump in that and living in the are my entire life played a big part as well.

This time I will Research, Study, Learn, Network before jumping in.