Meaning anything attributable to my personal life.

@Curt BixelI agree interest income attributable to your IRA's promissory note investment is not subject to UBIT provided that the interest is not tied to the underlying performance of the investment (i.e. the flip). 

In addition, if you are self-employed with no full-time employees you may wish to consider opening a Solo 401k instead of a self-directed IRA as it has several advantages over an IRA LLC such as much higher contribution limits, direct checkbook control (i.e. no need to have the account at a specialty trust company), ability to take a 401k loan, exclusion from unrelated debt finance income tax with respect to investment in real estate acquired with non-recourse financing, etc.In addition, please note if you purchase debt-financed real estate with your IRA, unrelated debt finance income tax should apply to the income attributable to debt-financed real estate held by your IRA.

We have a mix of ownership at the moment: 2 of them are owned by the LLC, the rest are titled to a single partner.We also have a mix of financial instruments at play: 3 of them titled to a single partner have a mortgage with a bank, 1 of the homes owned by the LLC has a private loan, and the last 1 owned by the LLC is all-cash at the moment.I'm less interested in asset protection from the LLC since we're using Umbrella insurance as our safety net.My main concern is filing taxes properly and accurately (attributing gains and losses to each partner correctly), especially since we started down only-LLC ownership and transitioned part way to personal-and-LLC ownership of our properties.

My personal feelings are that you are attributing too much emphasis on what you can prepare for by  learn from a book and the internet, etc,  and calculate from a spreadsheet.  

If debt-financed real estate is acquired via an IRA, any income attributable to such investment will generally be subject to unrelated debt finance income tax.5.

In addition, if you are self-employed with no full-time employees you may wish to consider opening a Solo 401k instead of a self-directed IRA as it has several advantages over an IRA LLC such as much higher contribution limits, direct checkbook control (i.e. no need to have the account at a specialty trust company), ability to take a 401k loan, exclusion from unrelated debt finance income tax with respect to investment in real estate acquired with non-recourse financing, etc.In addition, please note if you purchase debt-financed real estate with your IRA, unrelated debt finance income tax should apply to the income attributable to debt-financed real estate held by your IRA.

If you then take corrective action to remove the excess, any earnings deemed attributable to that contribution may be considered a non-qualified distribution and subject to additional taxes. 

If debt-financed real estate is acquired via an IRA, any income attributable to such investment will generally be subject to unrelated debt finance income tax.5.

If debt-financed real estate is acquired via an IRA, any income attributable to such investment will generally be subject to unrelated debt finance income tax.5.