I’m a technical designer in consumer goods.

I will now be paying more attention to that factor. 

And the HELOC payment will go up with interest rates and at the end of the draw period so you have factor all of that into your analysis.2) That depends on the terms of your HELOC.

Your success here depends on the quality of your list but good quality generally speaking could be 1-2% (so $25 - $50 per lead)FB prospecting is very untargeted as the person has shown no intent (you're probably just going to use targeting such as the zip code and potentially one or two other factors that you can target with using fb relating to home ownership and income or debt levels).

@Matt Morand If you use a PM, you always need to factor in the costs of bringing new tenant in.

These factors ultimately increased my mortgage payment thus reducing my cashflow to about $0/ month after accounting for vacancy, capex, PM fee, etc.

. $7500 pr year income assuming nothing goes wrong and 0% vacancy factor.  13 years payback to make my 100k equity.  23 years left on the mortgage. 

So cash flow is key in this situation, and then location and property quality are important factors so you can sustain that cash flow. 

You also might want to factor in what it will cost to get it rented, i.e., paying a realtor one month's rent to get a quality renter.Make sure you double check with your realtor about whether you can get $1300 a month for that neighborhood.

Based on many factors (location, condition of property, inventory, demand) it may be best to do the minimum.