I would tell the current renter that you are returning thier deposit as the property is sold and you anticipate thier max tenancy would be 8 weeks.

I do eventually plan on owning 20+ properties, would it not be wise to form an LLC in anticipation of that?

For example when the bank CD and quality bond markets were paying 1% or less, inventors are happy to make 5% on a real estate investment (meaning paying so much for the property that their net anticipated return is only 5% of what they paid). 

I’m averaging about $260 for the last two months, and anticipate similar for this month with 2 trips booked already.

We are anticipating buying another property in the next few months (likely a conventional mortgage) and not sure if we do the streamline for our current property if this would mess up being able to qualify for a new mortgage for a new property shortly after?

“Far more money has been lost by investors preparing for corrections, or trying to anticipate corrections, than has been lost in corrections themselves.” – Peter Lynch

I was anticipating having to make that decision at something like 9 months.2.

If you have a Heloc with nothing borrowed on it in 2017 is there an incentive to draw on it now with the anticipation you will want to use the cash in a few months to purchase a rental?

Being a great host is anticipating the issues in advance and preparing for them even before they happen.   

Beyond voicing your displeasure at his having lied to you, I wouldn't even give him a heads-up on this; just gather as much information on him as possible in anticipation of a lawsuit down the road.