Is there a totally different strategy to leverage low FHA loan down payments when investing remotely? 

they require a low 1.0 debt coverage ratio so as long as your rents cover PITIA expenses then your good to go, cash out is required to be used for "business purposes" only their retail division is Cash Call mortgage, FICO can be as low as 600 and cash out LTV's from 65-75% based on credit, I used to work for IMPAC as they were rolling out the product, it is pretty competitive in the market for this type of financing. 

Debt to income is not an issue, we have very low debts compared to our income.If we were able to find a private lender for 12 months is the best route to get a home equity loan after those 12 months are up to pay back the private lender?

I have purchased and done renovations on 10 houses and have gotten pretty comfortable with the process. however I recently purchased 3 turn-key units that left me low on capital.

The goal of a MF sponsor/syndicator (typically) is to return their investor's money within 5 years and deliver IRRs in the north teens or low 20's if you're lucky.

I have been experiencing awful conditions as a buyer, expected to pay record low cap rates AND accept giant material defects, quickly and with cash!

But I'm wondering if there is a better low-risk option for that money, which is just sitting there for a rainy day, that would help it grow on its own over time and allow me to withdraw funds as needed.  

I’m attempting the BRRRR strategy but can’t refinance for another few months due to having low equity in home.

I personally wholesale lease options, so I can work with low/no equity leads, and recommend everyone learn how to do that too.As for other marketing.

Like, super low.