If it is a regular rental, draw up paperwork that clearly outlines how much money they lent you, when it will be paid back and how much (eg if you buy a house for $400K and 10 years later they move out and it sells for $500K-do they get a percentage of the profit (after taxes and costs)?

Regarding Interconnection, keep in mind (same reference as the above link) "The typical project built in 2023 took nearly 5 years from the interconnection request to commercial operations."

Just didn't do a reference check, maybe that is the key. 

The strategy you're referring to could work in principle, but there are a few important considerations.

Start-up costs are also deductible but are amortized over 15 years with a limit of 5k.Start-up costs have strict rules and your case might not be the same as this one.Case Summary:Timeline line of eventsStarted investigating property: FebPut first contract (canceled): MayBought first property: December 30thWhether a taxpayer is engaged in a trade or business is determined using a facts and circumstances test under which courts have focused on the following three factors that indicate the existence of a trade or business:Whether the taxpayer undertook the activity intending to earn a profit;Whether the taxpayer is regularly and actively involved in the activity; andWhether the taxpayer's activity has actually commenced.On the basis investor testimony, we may assume that he undertook this activity to make a profit and that he regularly and actively engaged in it.

“Essentially, they are cutting in line,” Mills said, referring to the super-lien priority status over a mortgage.

I put in a brand new side by side stainless steel refer into the new kitchen.

WIll need to be a reference point for the thread as there are frequent Arbitrage questions

I've heard of people just putting their friends or family down as rental references and such, and forging pay stubs, but always hoped I would never encounter this. 

I found all sorts of things to reference for an eviction including excessive damage to the property, signs of an animal, lack of yard maintenance, oil spill on driveway, smoke detectors removed, the unit smelled of smoke, appliances that came with the unit moved off site ect...