There is an affordable housing crisis here in America.

But, it may not offer the ROI as other locales, and it may not be "fun" like buying in a favorite vacation spot.2 - The highest ROI folks - Self explanatory, will go where ROI is high and/or regulation low.3 - The second home/retirement minded - These people are looking for minimal ROI but want the house in a specific location because they like to use the property and want it to pay for itself.

I found a house that I like to purchase in a great neighborhood and the exterior looks great for a 1922 stick built house.

If you walked into a bank, your pre-approval would likely never qualify for a house hack duplex.Did they count 75% of the expected rent towards your DTI? 

Hence spec house.  

I recently found a house in Dallas (listed on Zillow for 120 days) that is 100% owned by the seller, and they're open to seller financing.

I'm a recent graduate and I was wondering how can I get access to a DSCR loan without having a credit score, not being an us citizen, now owning a house (some DSCR loans require that you own at least one other house) and not having a job.

The original goal, rightly or wrongly, was to maximize rentable units, so we rebuilt the main house from the foundation up into a 3 bed 2 Bath 1,600 sq foot main house, and added a 600 sq ft 1 Bed 1 Bath JADU, along with a 1,200 sq ft 3 Bed 3 Bath ADU.

Paying those things benefits you because they facilitate STUFF exiting the house. 

Recommend that she contact the state's rental assistance program, the victims' assistance program, and make other arrangements to pay or vacation within three days to find more suitable housing - like Section 8.Run your business - or risk having the tenant ruin it.