Just wondering how I could ever prove my parents house was my primary residence in case I was ever audited. 

Or just ask me about the 2 Roth IRA audits I directly handled.

A single member LLC has a high rate of IRS audit.

The key is that you would need to demonstrate to an auditor that your father had the intent to hold should he be audited.  

In preparation for this move we have taken a financial audit of our circumstances and see that our 401k (I have the only account now, just shy of $100k @ 40 and my wife has just begun to contribute to her own this year at 33) will not get us where we want to be in 25-30 years.

While you can find partners to take some of this weight off your shoulders, you're still going to need to put EMD down on properties (risking tons of money), your reputation on the line, your investor's confidence in you, due diligence costs (inspection, scopes, lease audits, etc...), travel costs if you're going out of state, and much more!

Given the potential conflict of interest, I'm thinking of switching management services  to someone impartial when the warranty period expires.  

They were also audited and billed on tourism taxes.

It also depends on the seller; are you buying from a Mom Pop who still use a ledger book or a REIT with audited financial statements?

Those come back to bite you if the file gets audited or your loan goes a little sideways.. being un truthful on an app to a bank is not good.