A single property is going to decrease your operating costs and make the property more profitable.The other reason, is that closing costs are going to start adding up with more properties.

I also look at the homes that have been on MLS for some time and help my investors make more reasonable offers to the sellers once they start decreasing their price. 

Sometimes the ambiance of a place will decrease your rental rates or your amenities don't meet the needs of higher quality tenants.Cap rates are at an all time low if you want to sell.

These can help you get around the debt:income ratio because you usually have an equity bump during the Rehab phase (thus decreasing the debt on the house).2) Private Lending- this is exactly what it sounds like.

Agree that it is a solid play, but question short term cashflow.In terms of your long-term plan, keep in mind much of our supply data indicates over-supply in mid 2018, which will result in negative rental annual rates of change throughout 2019 and some of 2020, decreased net-income, etc.

The "challenge" is to identify changes that can increase rents and decrease operating expenses, which will increase cash flow.Aside from operational expenses, you have an opportunity to affect cash flow through how you have your property leveraged.

The price drop is dramatic, but the rent decrease is almost non existant.

I am trying to avoid any unintended consequences . . . for example, may adding an ADU in a fairly upscale gated SFH community decrease the desirability of the house for prospective buyers when I am ready to sell? 

Quote from @Sam Barnsley: We're in a peak market, meaning there's a very good chance the home will decrease in value in the near future, or at least stagnate for a couple years before it starts gaining equity.It doesn't seem like a good time to make high-risk moves.

The second will decrease cleaning expenses.