Than your biggest issue is renting a place where the tenants will pay for their own heat.

My biggest success in REI is purchase of  1 bedroom condo for 30k cash that brings in $750 a mo rent and is now worth near 80k.  

These are some Wealth Creation Strategies that the Ultra Wealthy employ all the time as their biggest concern is Wealth Preservation.I know this was a 30k foot overview of the possibilities but like I mentioned, it would take a very long post including charts and narrative to go over the "fun" and being honest probably way beyond the scope of this forum.Get with a strong Attorney, Estate Planner and CPA to put the game-plan in action.

The biggest issue that I see here is that you called it $400 cashflow, when you don't have $400 cashflow, but $400 above mortgage.

We consider our pricing strategy and staging our biggest and best weapons when it comes to selling homes. 

My biggest concern is the rental market. 

This is probably the biggest risk to the buyer is when the balloon payment is due. 

Before I read @Joe Villeneuve 's response, I immediately though that I would ask about their biggest failures or best investments they NEVER made and why.  

That is the biggest reason I am interested in the job.  

I have evicted several "John Doe"s"Storing the things would probably be my biggest objection.