Just became a Plus member yesterday with the intent of posting a package of properties. 

For your personal home, you could do a version of this with the intent of anticipating expenses.

My intention is to flip it by rehabbing it as a single family due to it comping well with single families vs duplexes(higher spread) and the fact that the dividing wall was already torn down.

Intentional damage by the sellers or even a vandal in the mean time.If you allow them to stay beyond closing, you need to hold back funds at closing, sufficient to cover eviction, cleaning and for any damage that might happen - and you need to do a walk-through with a video within a few hours of closing to document the condition.Again, this is a very bad idea. 

I.e. we have no intention of selling.

The flip side is "going under contract" doesn't mean the deal went through, so it'd be a clear picture of intentions, but not necessarily results.

@Diana Muresan Isn't it mortgage fraud to buy a flip with an owner occupant loan and no intention to actually live there after you rehab it?

I find that strange because in my 25 year adult life, I have never intentionally or accidentally punched a hole in any door or wall.Also speaking to point 2 about charging for time, you are best to hire everything done.

Went back and forth from intention to Air BnB it to a straight rental.

If you move out of the property and change the use for investment and then use the property for investment purposes long enough to demonstrate your investment intent (there is no statutory holding period specifically but most folks feel comfortable at anything more than a year) you would then be eligible to do a 1031 exchange and defer the tax on the gain indefinitely.