The good news is that the financial metrics you've read about are universal and not at all country specific.The bad news is that Germany may just not be a good cash-flow market, compared to the U.S.But then, few markets are.That's why you find so many Germans and Australians and Spaniards and others trying so hard to find great deals in the U.S.And, even in the States, there are plenty of sub-markets where properties routinely fail the so-called "1% rule."

I guess the question would be something about how portfolios are treated during financing or maybe I'm not seeing it from the correct perspective.

Be prepared to followup numerous times.Highly likely the owner will treat your letter like junk mail.

This is actually a problem - since now you are treating them as one activity, they will carry forward indefinitely. 

I see people blaming the custodian for their bad investment because they had someone on their website.

Deals carry risk and you can't always control a deal taking a bad turn.

There might be a product you can treat the line with to help slow the process down. 

Fair Housing laws require us to treat all people equally.

I have a "friend" that has an apartment unit that consistently has bad tenants.

I don't think your second idea is bad to ensure things are found and documented.I ended up qualifying for a SBA disaster loan that helped when FEMA would not do anything since my properties are under a business.