.)- Do you have healthy working relationships with contractors/vendors?

A healthy percentage of higher density multi family properties are open to seller carry or owner financing.

Have done any soil testing or build studies so that you can transfer the land in a more opportune way than when you bought it? 

Depending upon that, and your financial health I would just recommend hanging tight and adding another avenue of future income.

For example, a 40-year-old healthy male might pay around $500 per year for a 20-year term life policy with a $500,000 death benefit, compared to $4,000-$5,000 per year for a whole life policy with the same death benefit.

These are the sellers OFF market that may accept a healthy discount, but these houses come with issues that may be cheap to fix or may be very expensive to fix.

There is a good chance the walls sit on bare soil and do not have propper footings underneeth. 

Be careful with the foundations, the soil is sandier so it's common for shifting to occur which will affect the plumbing. 

Some friend has been telling me foundation issue is common in Houston area because it is building on active soil, and the extreme weather might cause foundation issues here and there.

You know the answer well but are looking for a healthy discussion.