Your answer needs to make sense, and be true.Also refi'ing your current primary into an investment loan also has the potential to be fraudulent if your family still occupies it as their primary. 

Depending on your current rate or if the current loan is short term or long term.

Hello Bigger pockets just dropped the blog link attached with current hedge funds buying single family homes .

The current rents are really low because the tenants are responsible for doing any and all repairs on their buildings (which in my opinion contributes to the poor condition of the buildings). 

I believe they're almost 8% with that program currently but if it provides an entry point, you should consider it!  

The denominator in the calculation is your capital/equity and with no debt the return on your existing equity is low.

Congrats on your success in acquiring the duplex that now will yield 6.5% cap at current lower rental rates. 94115 is a great zip code to be in.

Securing funding has been challenging, particularly because my business documents reflect low revenue from only one duplex, and I am currently between jobs.I have identified a reasonably priced piece of land and have saved a small portion of the funds from my duplex sale to invest in this venture.

Is this a 2 bedroom apartment that is currently being leased (in the eyes of the CHA) as a 1 bedroom apartment?

You've done a great job with keeping your debt low so I have no concerns about your level of discipline to use/reuse a line of credit.All the best!