It's putting out lots of fires, managing finances like a hawk, keeping projects on time, in line and on budget, marketing the property & getting it through closing, and *then* doing it all over again - and that's if you're not doing any of the work yourself. 

The only ones that will pay are the same ones that would have paid when you filed for the eviction.

Short term it is difficult to make the numbers work, the cost of new construction and the time it takes to zone-plan-build are usually the main reasons why private investors stay clear.

Maybe the biggest "risk" might be the fact that you cannot occupy the property at all so technically if you run into hard times and need to move into the property thats not intended - but no real more risk. 

The most expensive piece we bought was the La-Z-Boy queen hideabed couch.

I dont do 100% development but have done my fair share over the years. 

I happen to live in AZ in the winter and MI in the summer. 

Even if you only averaged 2.8% appreciation annually, which if you've had it 20 years I have no clue how that's true given prices have well more than doubled in that time, youre skipping over the fact that you have been benefiting from that appreciation on the ENTIRE house, not just the % you paid for.  

Your starting depreciable basis should have been the LOWER of what you paid or the FMV in 2010 when you converted it to a condo. 

Far more than most real estate acitivies and much quicker think about it.. you sell the same info over and over and get paid instantly you have no roofs to fix no tenants to manage etc etc.. you do have reputation management of course.