To make the most of this opportunity, I'd love to hear advice on promising emerging cities to focus on, the advantages and disadvantages of each, and alternative financing methods beyond traditional mortgages

Sellers believe that by providing flexibility, they can attract buyers who might not qualify for traditional loans and, in turn, command a better price for the property.This perceived advantage can sometimes lead sellers to agree to terms that heavily favor the buyer, such as zero-interest loans or accepting second-position liens.

Looking at traditional financing for a 30-year.

Option 2: I found a house that the asking price is 930k , but I’m sure I can get a discount on it because it needs a lot of work , it doesn’t qualify for traditional financing , so I would need to take a hard money loan , it needs about 150k worth of work , the plan would be to offer the full 930k asking price but ask for a 6% seller concession , I calculated 20% down payment and 7% closing cost , so total after seller concessions comes out to 21% down payment which is $195,300 .

The "backdoor Roth" strategy allows someone who earns too much income to be eligible to make a direct Roth contribution, to make a non-deductible contribution to a traditional IRA, limited by the annual contribution limits ($5500 for 2013), and then do a Roth conversion by rolling the contribution over from the traditional IRA to a Roth IRA.

I am actually trying to lock down a private money lender so I might not need a traditional bank for the loan. 

I was wondering if I acquired another SFH via traditional investment loan, and either rented whole house/by the room - would the income count towards lowering my DTI?

You are comparing apples and oranges - i.e. sellers who place their home on the MLS without a traditional agent and those that never put their homes on the market but do a private deal.

We use the traditional lender and get 15 percent down How did you add value to the deal?

If you are working with the right team they close a lot more quickly than traditional loans.