Quote from @John Davey: Id appreciate any help, as ex. if i take out say 100k home equity loan and use 50k each as down payments/cloing costs my understanding is i cant deduct the interest?

That is under almost 1,000-year old principals of "equity" followed in English and then American jurisprudence.

The VA and Fha loans have been able to do it but their strict appraisal guidelines make it tough to buy the often older homes in my market in Virginia Beach / Norfolk Area. 

Due to the popularity and scarcity of these properties in Nashville, it would be difficult to find a property meeting the STR requirements given a proposed purchase price of ~$300-350k.Additionally, your situation is a bit unique as it sounds like you may be living away from your primary residence more often than not, and as such, I also recommend you confirm with a lender whether this situation would qualify for this type of (primary residence) loan.

I’m an ex realtor who also has some experience working for a private equity group for a short time before I got a really good gig in a completely unrelated industry that will allow me to have options when investing.

Joe its all about NPV  and rate of return for investors.. either way your going to take a pretty big hair cut out of your equity to do what your wondering about. 

They are a dual military couple so will use their other VA loan for their next house.They are willing to let us assume their current loan.

Question: Should I collateralize the loan (if using private or hard money), or rely on roll-over loans (to maximize the lower points and 3-4% rate)?

only one avenue to this and that is an equity partner that shares your dream. 

I’m a serial entrepreneur with experience in the tech and food distribution industries, now diving into real estate investment to build cash flow and long-term equity.