Hey BP,I have converted a couple long term rental units to short term in 2017 and plan to convert several more in 2018.  

The short answer to your question is that if the property does not have equity, then you will not be able to refinance it - unless you bring funds to closing.

The goal is to pay off the house ASAP so we can have a stable income when my wife and I retire in the next 15-20 yearsLet me know your thoughts or questions by leaving a comment.Here’s a short video I made on the renovation process:

I kept the deposit since they broke the lease, but would like to get the new renter in either on or shortly after December 1st so that I'm not losing much from vacancy.

Check out the Short Term Tental forums.

There are prolly some other items you want to do before needing to communicate with a CPA.1) You should develop a real estate strategy based on your strengths - Will you be a buy and hold investor, fix and flipper or focus on short-term renting.

what is the reference date to determine long term / short term capital gains for a real property?

You can do an air pressure test but it's important to note there are no short cuts.

Typically if they have plans to move they will not want to spend any money on the space in the short term.Howe far in advance do they have to give notice to renew the lease before exercising the first option period?

When a tenant calls for a service need it's beneficial for me; it gives me another opportunity to interface with the tenant and enter their apartment on short notice.