I have the cash flow in my budget to eat around $700 if need be, but this is not ideal because I am looking to scale.

Your number will grow exponentially, not linearly and your blind spots are expenses that you are too frugal to manage today but will eat at a higher price tomorrow.The goal should be to eliminate expenses via consolidation, have multiple sources of income, and carry low risk(debt). 

Car loans eating up a huge amount of income no. 

Check with the city on where they are install new sidewalks, outdoor eating areas, walking and biking areas.

What you really build with rentals is equity - but also as you have discovered you can’t eat equity.

But, this has absolutely nothing to do with living out of a line of credit rather than a checking account.Even not counting the opportunity cost credit given in the analysis for the “reserve” theoretical investment, the additional nickel and dime fees associated with the HELOC will eat up any savings.Perhaps you became much more vigilant at controlling expenses when you decided to use the HELOC to pay your everyday bills.

With longer leases it might be worth it. all comes down to your investment style. eats into the cashflow but you are more protected.also, my situation is different due to mortgage cost. your one properties rent is 2.5 of my properties. my average mortgage is around 650.  

These are important questions because renovations can quickly eat away at your budget especially if you don't have a trustworthy contractor.

What I have found through Google and forum searches is split between "everything is deductible" to "you just eat this cost."

It's harder to finance good properties right now for obvious reasons, and if you go NNN or DST then you need to be very clear about the costs (upfront and ongoing) that might eat at your returns.