You're going to have to scrap like crazy to break even - think rent by the room, short term, mid term strategies that require more work.

Majority of the houses are old and require frequent repairs in addition to a poor tenant base that can't pay on time and don't care about their credit.

Simply gifting him half the property now wouldn’t immediately allow him to claim the exclusion without fulfilling this residency requirement, I don't believe.One thought would be to use a HELOC to pull just enough equity out of the current home and use it to buy a smaller home, or at least the down payment.

I would be happy to go over some of the requirements for getting a mortgage in the US as an international investor. 

He offered to sell it to me with owner financing for $400,000 and only required 10% down, so I jumped on it.

It's easy to obtain, costs very little, and doesn't require extra, on-going effort to maintain.

A/C is not required in Texas as well. 

It’s not the most simple task unfortunately - definitely requires some technical skill.

I am considering getting into this space (looking at some courses), but worried that its too late, and that deep local market knowledge/understanding of buyers/connection with developers etc is required to make this work, which only incumbent/long term investors will have and would be hard for a new entrant starting from scratch to catch-up...is my hypothesis valid in your opinion ?

Investing in Bham Sec8 properties requires somebody with street by street knowledge.