I am a diy person but I realize that this is gonna take some help from a community of like minded individuals.

We missed some simple things on inspections.

There can be a lot of details to this, and one can easily get lost in the details but pull-back and keep vision of the fundamentals as it really is rather simple. 

I'd then be paying my heloc off at 1.75% simple interest rather than the original mortgage loan with 4% compounded interest.

For numerous reasons, this strategy is not anywhere near as simple as it appears, and the risk of default problems can be quite high if the seller is inexperienced or unknowledgeable.    

A professional may often do a better job when it comes to hard decisions as it's just business to them.A DIY landlord though, may babysit their tenants a search high & low for the cheapest contractor and then pay them cash to get an even better price.- A PMC is not going to go to the extremes owners do as a PMC can only afford to spend X amount of time on problems for owners - or go out of business.

Also check out webinars by profit coach, Evernest, Lead Simple, Peter Lohmann, Wolfgang Croskey, and I know there are a few others, but thats a good place to start. 

That's a simple fix when needed.

Simple answer how ever you can. 

KISS(Keep it Simple..)Reasons1) What are you getting in return for living in the property?