In my area section 8 tenants tend to stay longer and in many neighborhoods section 8 pays a higher rent.

Since REP status is difficult for full-time doctors to achieve, this approach allows them to take advantage of the tax benefits (e.g., cost segregation studies and bonus depreciation) without qualifying as real estate professionals.

I would recommend you speak with your tax advisor and set it up correctly from the start, whether an LLC, Trust or something else.Also consider states different laws, maybe find a state with more friendly landlord protections. 

Debt and Long-Term Strategy: Old House, Nearly Paid Off: By keeping the older property and paying it off within a few years, you could use the increased cash flow to either fund repairs or reinvest in more properties.

I got the early bird rate and the total was $3,536 (all-inclusive, taxes included).

That doesn't include taxes, insurance, property management, vacancies, and other expenses.

No one was able to clear it, even after multiple attempts, and it caused Home365 to stopped paying my bills (pending owner contribution).

We have had much more sucess buying foreclosures, REOs, Sheriff Sales and Tax Sales where we have bought hundreds of properties. 

Well, the reasons given generally fall into two categories - either tax benefits through an “installment” sale or obtaining an interest rate on their capital greater than what banks are paying.In my 45+ years doing real estate deals, I’ve found maybe once that the tax argument was considered by a seller; further the “greater than bank rate” argument is completely irrelevant because - the proceeds of a property sale were never going into a bank account, at least not most of the proceeds.

A lot of house hackers downgrade their income to pay less taxes.