And from what i've gathered through reading the text messages and emails the tenant had sent to my parents, the tenant really did just install the AC without notifying us. and true, I don't know the extent of their business relationship, but it looks very professional and healthy to me. 

"I thought condemning the property results in termination of any associated leases"That may be true but I would doubt it.

Depreciation is not factored into cash flow calculations, you are correct.It's going to be tough to find a true 1% deal on the market, and it has been for a few years.

But a true income statement will also have "below the Line" items like depreciation, debt service/interest expense, maybe partnership level fees, etc that are not driven by the property operations.  

(I know sounds too good to be true)The property has a 10 year tax abatement since it is new construction in Philadelphia therefore I only pay about 16/month in taxes.Final monthly payment: 1550Estimated Rent 1800Cash to Close: 10k~30% yearly return.

That would have been the easiest and cleanest way I believe.So with all of that said (hopefully it makes some manner of sense), how can I keep track of each property's true balance and when each property has fulfilled its debt to the HELOC and we can start splitting the cash flow 50/50. 

Bouncing off of what @David Clinton III said because it's absolutely true! 

What your family co-signer is saying is true.

That would have been the easiest and cleanest way I believe.So with all of that said (hopefully it makes some manner of sense), how can I keep track of each property's true balance and when each property has fulfilled its debt to the HELOC and we can start splitting the cash flow 50/50.

I also assumed no closing costs but that is probably not true.