Perhaps focus on cash flowing condos as an easier entry or team up with another investor in a JV relationship. 

However, the profit treated as capital gain would not count as income for loan qualification purposes, thus lowering his income (of which the profit was a significant part of income for the year).

Prices are rising so that won't last forever, but it is there.Big difference - 1) The police respond and are active in enforcing laws to protect your tenants and homes2)  The schools are much better3)  The crime is MUCH lower  4)  You will be happier with your property manager5)  The homes will actually sell to end buyers, not just out of state investors.6)  People pay taxes and water bills in every city other then Detroit nearly all of the timeCan you make a HUGE return in Detroit! 

You can try a lower flat fee company or do a FSBO. 

In my experience, the vast majority of people with emotional support animals are under 30 and lower income.This is just one example of how weak our culture has become.

Usually rentbacks call for higher rents than market, not lower. of course, those situations I've seen have always been short term. you make it sound like this can be several months. in that situation, I would tell them they have to pay market rent, and provide security deposit.

I purchased a duplex and want to submit my appraisal to the county in order to hopefully lower my taxes.

I can give you very high level calculation to understand both scenario...Lets say you buy 100K house with 1000 rent... lets compare all cash against leverage...All cash InvestmentYearly return = 12000 (Rent) + 2000 (Appreciation) - 3000 (Tax + Insurance + Capex) = 11000 = 11%LeverageYearly Return = 1000 (Rent Cash flow) + 2000 (Appreciation) + 3000 (Amortization) = 6000 = 6%Now when you leverage investment at 20%, you can buy 5 house from 100KYearly Return of 5 Houses = 6000 X 5 = 30000 = 30%There are more tax benefit in this deal also as your positive cashflow is lower...If you are planning to buy multiple houses, Leverage is always better...

Modern, direct vented, natural gas and propane furnaces are typically in the range of 92 - 95% efficient.Your decision on whether to replace the furnace will depend on the efficiency of the current unit and whether it make more business sense to replace the furnace or to add a heat-pump with an exchanger insert to the existing system ... and, it is (or should be) primarily a mathematical decision yielding which ever approach is going to offer the shorter payback and lower operating costs.The math aside, there will be other non-math factors.  

When the demand is concentrated in the entry-level and median price ranges it stands to reason that the luxury market which has an over-supply would contract proportionately.