While leveraged real estate would result in UBIT in an IRA, the 401k is exempt from this tax if it owns financed real estate.If you need any further clarification please feel free to contact me directly - would be happy to help! 

I'll agree with @Ashish Acharya here: if you're wanting to sell the property primarily as a way to get some tax-free cash, then yes, sell within three years after moving and you qualify for the $250k(single)/$500k(married) Sec 121 exemption.

If I recall correctly (although I can't find that citation), that exemption also applies to officers of a corporation.

Exemption from realized gain on QOF investment held at least 10 years Gain on subsequent appreciation is eligible for permanent exclusion if QOF investment is held at least 10 yearsUnlike retirement, you don’t have  I wait until Forever. 

Is it possible to obtain a policy that will rachet down once we complete the work, or provide a short term exemption if we escrow the funds to replace the panels immediately?

About 1/3 of the deals fall through at their end because people "have stuff happen" in their lives like Job Loss, Lose Momentum getting credit cleaned up, Medical Issues, Divorce, "Changed their mind", Don't REALLY want to be home owners, etc.

If you want to live in the house and title it in your name you get tax benefits upon sale (if occupied 2 years as your primary residence 250K if single and 500K if married) gains are tax exempt.

This tax is meant to protect tax-paying businesses from unfair competition from tax-exempt entities.The use of debt-financing creates exposure to taxation known as UDFI on the percentage of the income the IRA receives from the non-IRA (borrowed) capital.

Property-taxes wise there are exemptions but I don't think there are any that a real-estate investor could realistically take advantage of.

Medical hardship is something where we should have a heart and try to understand where they are coming from.