For example if investor A has 5 duplexes and investor B has 10 and they both have the same amount of money to spend on those units, that's 5 more roofs that need to be replaced, 5 more property taxes to be paid, 5 more sidewalks that crack and need to be replaced, 10 more water heaters to upgrade, 10 more furnaces that eventually go bad, 5 more yards to mow and do snow removal on, 5 more PM's if that's your thing, you get the point. 

If you are the original purchaser of the unit (HVAC/water heater etc) and you have registered the unit, labor warranty usually lasts for 2 years and parts warranty usually lasts for 10 years.

As I came up with ideas, I emailed them to myself from my phone so I can go over them in the morning with fresh eyes.

The answer is - YES - if you get them a legit P&S package - the property should have a enough equity for a flip - or under water for a short sale. 

No need to muddy the waters. 

Have you advised the tenant that the dirty water resulting from the powerwash would dirty up the windows?  

Call the local water company they will tell you. 

That said, what didn't pencil was the over-valued land price, the cost of running electric and water hookups for each of the houses over 40 acres, land-clearing and excavation, and the amount we anticipated people would be willing to pay per night extra for glorified camping.  

Auction.com seems to be a good choice (never bought though, only looks fresh and neat).

It's a 3/2 lakefront property (more like man-made channel-- no boats, fishing, or swimming), and the minute you open the front door, you see right through the house to the water.