There was an article published this week about a tax preparer who incorrectly filed returns for years and now her clients owe a combined $1.4 million in taxes following an audit. 

After a fourth visit the problem was fixed and i was able to access my accounts but after over 40 days of it being suspended with no real explanation of why and missing 6 payments which in turn dropped my credit score over a combined 140 points now preventing me from getting a refinance on my home among other things .

How do you come up with a value for the combination since I believe the home is not in very good shape?  

You didn't say exactly what this person's job function will be, but I would think with that many units you would need/want three dedicated numbers.  

Rate and term don't need seasoning. 100% ownership in LLC for the borrower or combination  of borrowers.

The other concern was that one of the water heaters was well past its life expectancy despite being functional.

There just is not the necessary case law for anyone in this industry to provide certainty as to whether such a transaction would be OK.So, the bottom line is that there is at least some minimal level of catastrophic risk for your Solo 401(k) in trying to combine funds with your parents.  

Most of this was from our naivety and inexperience combined with their lack of scruples.  

It's really difficult to invest with no support from your other half especially when your finances are combined.

But what would you guys say about a house that is 8 years old and has a currently functioning HVAC unit.