With the homeowner involved it gets a LOT more complicated on the legal, financial, emotional front and you’re dealing with someone whose mindset as to risk is a lot different than the professional investor.  

Also, I have a month to month tenant in the SF, which could complicate the sale. - Conventional purchase with 20% down using a HELOC: Current cashflow from the SF could cover a big portion of the HELOC payment, but this starts to feel risky from a cashflow and funds available for rehab.- Conventional and move there/rent out my primary: Certainly the best option, but a hard no from my S.O.'

As an investor that is WAY too early and extremely complicated to achieve the transition to a Title.If you guys need a call with me to clarify anything let´s share a virtual coffee (or beer, depending on time) and talk some Real Estate.

Plus it is less complicated to pull off. 

Unfortunately, I learned very quickly that QB was too complicated for me to use.

It was very complicated and cumbersome to set up properly and difficult to use.

If your household income is less than $150,000, you can save on taxes without a complicated strategy.

However, be aware that this might complicate things with the rehab and if you intend to claim tax benefits associated with rental properties.

Read this book first - https://www.amazon.com/Every-Landlords-Property-Protection-Guide/dp/1413307000 - before getting into more complicated and expensive measures of protection.

Quote from @Joshua Batson: Don't make it so complicated.