However, if you're specifically set on one of those markets I'd recommend Kansas City - landlord friendly state, lower property taxes, increasing population and diverse economy, a good supply of potential rentals that product good cash flow with a decent chance of future appreciation.

Applying for a primary residence HELOC on a duplex, in the range of $110-150k to perform some renovations and use for down payment on new duplex purchase.

Once in a rare while someone will say a number that is actually below the range of what I was prepared to offer.I will evaluate every lead as a flip, BRRRR or an assignment to give myself options.

Some people STR a literal 100 sq ft Native American teepee...doubt you'll find many takers for LTR on that thing.That said, portfolio diversity is important for lots of reasons. 

The realtor that wanted to introduce me to one wanted a finders fee of somewhere in the 12k range.

These were largely sourced pre-CV19, so eat the fish and spit out the bones.The DTI percentage range varies by lender, and is less than what you will find for an owner occupied property, due to lender risk.

Obviously that land and common area has expenses (ranging from insurance and taxes to maintenance) and yet can’t bulldoze the building on their property.

For me, not feeling safe is a hard pass.Houston is very diverse and large.

Similarly with the rent ranges - make sure you get opinions from property managers, online tools (rentometer, etc...) to see if your rental estimates are current.

Do other comparable units in that area/price range provide them?