But like you mentioned, don't forget guests need room for their items too.

That includes planning for and anticipating large repair items and having a reserve for that.

From my experience (I could be wrong) there isn't a format but the estimate should list details like the materials to be ordered and the hours of labor needed for each repair project (for example the kitchen cabinet installation or exterior doors) along with a cost listed for each line item.

People still travel for business, if you can capture that, you'd have more demand than you know what to do with. 

At this point, I am willing to consider subscribing to a data service if that is going to give me access to all or virtually all of the items of information I need.

Property management (pm) should be a line-item in the rental investing scenario, not a ways to cashflow or break-even .

Buyer tells them the item doesn't match the description or something similar, paypal pulls the $ from my account to refund them.

However, the largest line item in any new home construction cost for this type of home is the Builder, followed by the framing package and then the foundation system. 

You just need to shop around more and take care of the big items, like the roof, if needed.

In general Land purchases very much depend on the end goal and end use you have in mind, then once you have that defined there will be various DD items to complete depending on that use and your intent to develop, hold, or sell it.