Realize the historical appreciation realizing it goes in waves (so short term depreciation has occurred but the long term appreciation has for over 50 years surpassed inflation and virtually every other market). 

Best to deal with problems up front, before they occur, when cooler heads prevail.Good Luck!

I started out by accident! 

They do not want to fund a project and then rent per sq ft does not equal projections or little to no lease up occurs.

For instance, there could be a great chance for an amenable loan modification or a deed in lieu that could occur even in a long foreclosure state that would alleviate the inherent risk of a long, drawn out foreclosure.

Mail mishaps occur and so do on-line mishaps and bank handling mishaps.

If your agent is throwing away 75% of the properties before you even get to see them, you are at a severe disadvantage.I also think you are way over-estimating the number of pocket deals that occur in any given market. 

Or, are you counting on the steady appreciation that has occurred during the last 3 years to continue over the next three?

That's a persuasion technique called "thinking past the sale"  Get the other party to think about what things will be like after the sale and it mentally moves them to a place where the sale has already occurred thereby making it an easier decision to accept the sale. 

Upside-down deals typically end up in foreclosure or short-sale... or the owner simply keeps paying the mortgages.They are bad candidates for investors because there is no equity to work with.Until a foreclosure occurs and junior liens are wiped out, there is really nothing to work for.