Total newbie here but have been reading from afar about how to leverage/extract equity from a primary residence using a HELOC and want to validate an approach/idea/though to see if I'm following this properly. 

That is a way better approach than having a manager that is burying their heads or one that is taking such a hard line that residents don't respond and choose not to pay out of spite.  

If you approached me with this idea I wouldn't need any profits from the flip to be happy, and I'd still work incredibly hard analyzing properties, running comps, negotiating offers, etc.

But a less disruptive approach might be to gradually increase rents over 2+ years to try and maintain occupancy AND rents.Good luck!

Or if that's even an approach to take.

How should I approach them for a referal fee/mentoring option?

As a landlord, what is your approach to reviewing your property after the tenant has moved out.What do you look for specifically?

Thoughts on this approach?

I was able to get 4 family and friend investors after my 3rd brrr, but the other 20 I approached weren’t so keen.

you need to make it into a legal unit- egress windows, separate entry, meet minimum height, kitchen/bath with code requirements- be careful about taking the pirate approach.