Sec. 1.167(a)-(11)(e)(1)(i) provides that property is considered to be placed in service when it is “first placed in a condition or state of readiness and availability for a specifically assigned function” (emphasis added).

They use a percentage when maintenance/cap ex is not primarily a function of rent. 

How practical is acquiring land to dev mini home/1-2 Bedroom functional home? 

It's a game of hot potato.Short-term rental valuation is a function of = Interest Rate, Replacement Cost, Cash Flow, Appreciation, and some others like Insurance/Easy of Operating/Taxes.  

Cap rate is a function of risk and desirability.

The top issues include: - P trap improperly plumbed in bathroom- Moisture stain in one of the bedrooms- Double taps in electrical panel - False ground, or "bootleg ground" - Outlet GFCI not functioning - No air filter and nowhere to place one on HVACI'm actively looking to see if any  contractors can go over there with my real estate agent or look at the inspection report and see what's going on.

S Corps primary function is to reduce self-employment taxes, and rental income is not subject to these taxes.

Once you have a short list, get an account with each one and run them through the wringer to see how they function.

The exact amount above market rent is a function of how big a PITA they are

I wish AT&T had a "multi-account" function.