If she's been there less than a year, that should suffice.

And if not, why build a tiny house when an easier and cheaper cabin would've sufficed, or even better, a tent site.I'm not down on the venture, but to me it is a business venture, not a real estate investment 

Suffice it to say I would like to look for another tenant as soon as possible.

Or will one blanket purchase contract suffice? 

In that case, usually a Bank Statement will suffice.

Honestly for most purposes something 8mp and up should suffice.

You could take them to a nice dinner if that would suffice…

Having rental history via a schedule E in your tax returns would help, but an executed lease agreement and proof of security deposit and/or rental income received should suffice. 

This makes it very difficult to get a sufficently large discount for a property that is in need of work: the market overpays for less than perfect condition.So, what happened?

Cash flow would be slightly more with 4 single families, but we're not looking to get rich quick here and the cash flow on the commercial building would suffice, plus appreciation, paying off debt, and doing small rehab to the vacant property along with renting it out would increase value with additional rent.I run a business with 40 employees and understand the business side of things pretty well.