With 15 units, it would take too long. 

It really is a different animal than either long term or short term rentals so it's best to seek advice from others with experience in this niche.

As long as the Lease is in place, you do not need to return the security deposit, one of the reasons being, is that it can be applied to unpaid rent.

Not really concerned with how long it takes, I plan on doing this for good no matter how long it takes.

A little more work, doable, and safer in the long run.

As long as the money is green anyone will accept it.Good Investing...

After the renovation is complete - you can either sell the property or refinance it into a long term DSCR (debt service coverage ratio) loan.

As a side note for education expense, you may deduct education that maintains or improves your current job skills or that is required by law or your employer - as long as the education does not qualify you for a new business. 

We purchased the property in 2020 as a primary residence and then turned it into a long-term rental in 2022.

To make an informed selection, examine your long-term goals, overall expenses, property condition, and market competitiveness, talk with a mortgage expert, and investigate house hacking options.