When the IRA invests in real estate using debt not only does it have to be non-recourse but the IRS says, you can use leverage but since you aren't only using IRA money for this investment the retirement account is going to pay UBIT on the income generated because of the debt. 

However, our tenant turned out to be problematic—late payments, issues that led to an eviction, and additional repair costs before we could relist the property for sale.Now, after months of making mortgage payments out of pocket, we finally have an offer.

While I do maintain a relatively modest percentage of my assets in money market instruments, corporate debt funds, and high dividend stocks, I remain most comfortable with the investments I specialize in and know best.  

I wonder if an inspector's license might be another good addition to our repository.

Additionally, we are approved with the Better Business Bureau (BBB).

As for valuation, I see no reasons why a Junior ADU would negatively impact additional housing unit.

A less then full investigation may result in one thinking that the house and or the house and tennis court lots were what was being sold.As I later found out, a newbie tax lien investor thought they were getting a great bargain by outbidding other misinformed investors and paying the back taxes, legal fees, and an additional $34,000 (overage) which the county forwarded to me.  

@Shayan Sameer If you can service all debt and property expenses and have money left over then I'd say it's worth it.

Trying to decide if we should use a home equity loan for the remodel, do we need to put current home under LLC to help with debt to income ratio & would that affect getting the home equity loan?

Eliminate debt, establish a budget, and save.