Congrats on diving into real estate investing after four years of BiggerPockets soaking—that’s some serious prep work paying off!

We’ll pay to get it fixed that’s not the problem.

Your income isn't high enough for it to make sense as a rental and the closer you get to your residence limit the greater pressure you will have to sell it before losing your exclusion in whole or part. 500k right now can make $15k per year income with zero maintenance or tenant risks. 

Otherwise, you could network with a local Realtor to your area and see how many duplexes sell per year within your acceptable driving radius.

If you want to keep it, then would you refinance that new build to pay back the HELOC? 

If this is simply you not wanting to accept partial payments and the rent is current, stop accepting it - and send a Lease Violation/Notice of Quit for Non-Payment of Rent - and force the full rent to be paid per the lease or start eviction.  

That ROE is actually including what I'm paying on the loan principle so it's not even real cash flow, just money I'll get back when I sell.

Happy to pay for your time.  

I take the approach of the investor pays me a fixed fee to learn this on their own so they never have to pay me again if they don't want to.

I haven't seen any quads in our metro make more than $2k per unit (unless in 78704), let alone $7k, so not sure where those metrics come from.