TX has homestead exemption I believe? 

Church is property tax exempt.  

Depending on your state, you may also have judgment creditor exemptions too. 3.

Zoning must be residential, recreational, forest, or agricultural (remove the commercial, exempt, government, etc.)5.)

When you turn your primary into a rental you will lose the primary residence exemption.

We typically see 1-1.5% and in suburbs usually 2-2.5% even in Indiana if an investor its often higher tax rate then Chicago even though everyone thinks Indiana is low taxes its really just low if homeowner exemption there.

I'm not connected enough yet to put that money together but I will try.118 Apartments and 1 CommercialPlus$23,799,000 $19,386,000 $16, 720,000 Apartment Complex $6,000,000 Below Value for Quick SalePartially exempt from Rent Control Discount For Quick Sale Desperate/Must Sell 9% CAP RECESSION PROOF INVESTMENT-TRUE HEDGE AGAINST INFLATION$9,884,381LOAN AT 3.65% FINANCING FOR 7 MORE YEARS DUE JUNE2030 CURRENTY AT FIRST REPUBLIC BANK.

I see no mention of the federal estate tax exemption limit and its role in decisions.  

Some landlords are 100% exempt from Fair Housing Laws.

Also, in the OP example since the living spouse sold within 2 years, can't they claim the husband and her lived in the house for 2 of the 5 years and get $500K exemption.