I focus on "actual" cost, instead of "total" cost, and numbers with "$$$" in front instead of numbers with "%%%" behind, and found (Created) more deals out of thin air (OK...maybe a little less thin), than the obvious ones that everyone can see...and then end up competing with eachother for.I learnt that almost all solutions to every problem (not just in REI), are hidden right in the problem...in plain sight. 

As per switching to forced air, it really depends how the building is set up. 

Does anyone have any experience with rehabbing apartments without installing central heating and air?

If your friend moved in while you were still there, or got the keys from you and moved in right after you left, then they can probably argue that "you" never moved out, but instead sublet the place without permission.In this case, there's a good chance a judge will say that you do owe the rent (plus any damages), and it'll be on you to go sue the friend for it. 

Photos were recommended in cases of foreclosures or property damage/blight.2) No rescheduling...you will be assigned a day and have to show up (guess there were a lot of no-show's who wanted new appointments???)

One that is typically in a good neighborhood that is extremely run down, outdated, damaged, etc.

They'd leave and could care less they were leaving me holding the bag for their unpaid rent and damages. 

While mold itself is not as big a deal as people think, I'd make sure I knew how much damage there really was, and what all will need to be done. 

The possibility of bad tenants causing damage, or not paying rent, which could lead to negative cash flow, etc.  

This fund also goes to pay for general maintenance and upkeep items like air filters, light bulbs, and any other non-cap ex expenses.