Sorry to hear about the bad neighbor situation, that can always be an irritating inconvenience. 

So they are not going to stop lending, what they are instead going to require is that you have more of your own skin in the game if you’re going to borrow from them.

Make sure both of you have skin in the game and expectations clearly spelled out.

Speculating that your nephew might be lying to you about something & did something to irritate/motivate the LL.Every showing have a can of stink spray handy before they want to show the place :)

You’d likely need some money down so the hard money lender has you with skin in the game, but it will be lower than a conventional loan down payment.  

A lender will want to know that have and are prepared to put some of your own skin in the game.  

GP Skin in the game: I know this has been debated quite a bit. 

Again, put some skin into the game. 

There asking price is $154,900 and there is not much skin in the game, Zillow bought the home 3 months ago for $ 142,500.

A licensed attorney or CPA would be necessary to get real answers.Some concerns:The lender may not issue a loan to you if your skin in the game is coming from another party.The hard money loan would need to be non-recourse if the IRA is involved.The IRA may have exposure to tax on unrelated debt-financed income.The presence of the IRA in the deal could complicate the post-rehab refinance, which would need to be non-recourse if the IRA is still in the deal.