With a short stay the practical advice I can give is to hold back a significant portion of the funds until she is out, and have a stated daily penalty following that date.

I am guessing daily averages, occupancy rates/days a month occupied, that type of thing? 

That is not conducive to your time or the lenders given that rates change daily and a quote you get today wont be valid in a day let alone 3-6 months when you want to purchase.

I have a higher daily rate once the lease expires, that generally motivates a timely move.

Theres definitely nothing wrong with just jumping right in, you will be forced to build your business / lead generate daily.

If it is your first property then its better to househack because you'll learn all the aspects of having a real estate rental daily. 

But, with the chance to make 4x what an LTR would otherwise make ... there must be something else brewing.Now consider this: NYC currently has more Air Bnb listings than it does apartments for rent - putting a downward pressure on daily rates even though home values continue to increase. 

Much better than the average daily rates that you're seeing right now. 

Don’t pay off your house (that is debated daily - dead equity or deploy into another investment, direct real estate or otherwise).

They are done daily.