Those items boost your chances of success renting/showing the unit and enhance it's overall aesthetic, but aren't necessarily required for a new tenant. 

If you burn a seller, there's a 50% higher chance either he owns something else you're offering on or he knows the seller or his attorney knows the other attorney, broker knows about your past deal, etc.

Take any of Professor Chance's courses that you can.

Chances are, someone else has already asked it!

There's a very good chance the issue(s) you face have already been discussed and answered.Ask questions in the appropriate forum.

I think there is a great chance to get some long term investments in areas where the growth is not happening yet or just starting to happen.

@Angela Simon, If it wasn't your son there is a small chance that your accountant would let you purchase the 50% of the property you don't own. 

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

(The power company in MN will offer you a chance to buy the warranty after the furnace/ac is broken and come back the next day to fix for free.)