At one point they got a whole load of donated NEW dryers; these were gas dryers.The good news is that around here lumber prices have decreased significantly from their crazy high over the past year or so. 

A few options you might investigatehome equity line of credit on your personal residence, assuming you have the equity to do socash out refinance one of your other investment properties, again if the equity is therecross collateralizing all properties with the new subject property in one loan to decrease the total LTV (blanket loan)you mention partners.

Our ADU has a long-term tenant, so it sounds like I should be able to show the lease and inquire at the assessor's office about decreasing the tax rate to 4% then (thank you for the tip on that, Troy!).

If your lender is doing hte math correctly, I'm hearing that you for lending qualification purposes your rentals are decreasing your overall income. 

There is no Seller "leveraging the equity" based on value increase (or decrease). 

My partner and I have had our eye on a property for a while but never pulled the trigger because we were hoping the price of the property would decrease.

If you're living in the property, rent is decreased or non-existent, affecting the property's ability to generate income.RESPA rules are real and have a purpose. 

Generally speaking, holding rents lower will decrease turn over.

It only appreciates or decreases in value a percentage of the change in my neighborhood median income from the time I bought, 2012, to the time I sold... yeah my situation is crazy!!!

You may want to double check your numbers. 1.5% or even 1.6% on a fixed 30 year loan seems off, as a result that will increase your expenses, and decrease your monthly cashflow (probably putting you close to zero if not negative).