However, I'm unsure which of these platforms supports specific search criteria such as non-paying tenants, code violations, absentee owners, vacancies, tax liens, deceased properties, probate, and inheritance.

I'm a 401k administrator if you want to jump on a call with your advisor and I to go over that option.

Tenants, "go into Holiday-mode" and start spending disposable income (and racking up their credit cards) on Thanksgiving feasts & trips, Xmas presents & trips, and finally NYE plans.3) Income Tax Refund checks start being received towards the end of February and corresponding, the rental market starts picking up again as tenants payoff their “Holiday Hangovers".4) Spring Fever starts, sometime in April-May, causing both sales & rental markets to start picking up.

The PMI should be tax deductible (talk to your CPA, i am not giving tax advice), and your rate is hopefully in the low 3s.

I’m doing some research on tax sale in GA, a newbie  question if there is a municipal lien or mechanic lien or other personal liens,  will that be wiped out after foreclosure of redemption ?  

Motivation is an emotional response to a circumstance, not the circumstance itself.Someone in foreclosure, job loss, tax liens, are all circumstances.

In Hillsborough County, FL (Tampa), the structure value is deemed to be the Tax Assessed Value with the County Property Appraiser.

No, the taxes and insurance, along with HOA dues if required, are part of the payment and are taking into account.

A 1031 exchange would allow you to sell the property and use all of that equity and deferred tax from the profit to purchase something that would produce better cash flow from the beginning.

We do get a better fee/split structure, and that's a fair trade for the extra work of managing a large investor base and it's associated extra accounting and tax reporting overhead.I also find the advice in the OP to be contradictory.