I suspect they were talking about difficult turnovers with problematic renters, bigger repairs, heavy cleaning, maybe some missing rent, and longer vacancies. 

What am I missing? 

I may be missing something but why not just borrow the hard money to buy the property at the lowest price and pay back the loan with his same payoff plan.

When I purchased the house, the second unit was already occupied, and I decided to keep the tenant.The tenant has been living there for the past 3 years and had not missed a rent payment until a few months ago.

Lease renewals have a strict deadline. if you miss the deadline and fail to request a rent increase, then you will need to wait until the following year. 

I actually make my own greens smoothy / drink often but when I am on a writing heater and don’t want to pause, I grab some AG1.

Now that they've missed two reporting periods I'm wondering if/what action I should take.

Stop hanging out with your deadbeat buddies who spend all day drinking, talking sports, and otherwise wasting away.

Year 1-3.We have 4 kids all older between the two of us.Our ultimate goal is retirement and generational wealth.Each kid will inherit one duplex and we want to teach them as much as possible.Does this sound like a good plan,Or am I missing anything?

I'm surprised I haven't seen any talk of this in the forums (or maybe I just missed it).