The exterior is terrible and needs to be redone, the inside looks bad too with the ceiling and walls falling apart, and I'm guessing the hvac and other systems will need to be replaced.My question is, can somebody give me a ballpark estimate of how much it would cost to rehab this house?

I have seen people try and it looks terrible. 

Maybe I'm just terrible at mathematics, but I'm struggling to figure out how to calculate ROI from a house purchased via my HELOC.The numbers I'm giving below are just examples.Let's say that I find a rental property which costs $50,000.

Hi, I would like to hear from other experienced landlords how long it takes for you to get an apartment in rentable shape, I'm talking in a situation where  it's not in terrible shape, kitchen bathroom are ok, walls aren't Coming apart .

On the 3rd day of him living here there has been a foul, terrible smell.

Also, though 10-16% isn't terrible by any means, once you start getting that balance paid down and you see a little bit of a boost in your score, consider balance transfer cards with a lower rate.

Hiring a title company is not terribly expensive. 

Yes, if you are only doing it for getting the property through the back door, destroy peoples credit, and toss them out on the curb, that is a terrible business strategy unless you don't have a soul. 

As it turned out, the property is terribly mismanaged and way overpriced.

Even the ones that own their own rentals may be terrible at it.