@Chris Stephens I'm sorry I am a bit of a beginner but can you explain what you mean in this equation, I've read about it before in separate posts about wholesaling but never understood it because wouldn't you need to renovate the house which is considered flipping not wholesaling?

Margins are indeed smaller for option 1 but your velocity of money is much higher, meaning in the long-term you can buy more of your own Airbnb units/have more of your own equity, thus creating more cashflow.

If someone is open enough to share them with you, then by all means!

House hacking would mean buying a multifamily 1-4 unit and renting out the units you are not living in.

But just because it isn't right for me, doesn't necessarily mean it won't be right for someone else. 

The problem is that the way the property was renovated means that it does not allow for two couples and a shared kid (and maybe one more one day).

OP said income will quadruple in 2019, read that as meaning debt will be paid off.

That means that it will take me 10 years until I have enough cash in my IRA to buy the next property.

"Investing" means (or implies) that you bought property to own and run it for its income.

Meaning you pay the bill but then you send an invoice to the tenant therefore making them ultimately responsible for the water that they use.