Germany - A Genealogical Twilight Zone?

Greeting from Canada:

Names being searched: Renneckendorf/Wahl   &   Wright/Rapien

Unlike the other countries we have been researching in (UK, Switzerland, Canada, USA, etc.), we seem to have run into some unique issues related to researching ancestors from Germany. Perhaps you have run into similar issues and would be willing to share your tips for legal and
cost-effective work-a-rounds?

My wife and I have been able to successfully document some obscure lineages back to the 1500’s, but our two main blood line surnames have come to a full stop in the late 1790’s in Germany … my paternal side, “Renneckendorf” or its many spelling variations, has ended in 1791 in the Oschersleben, Sachsen-Anhalt  region. The trail has gone cold as if my relatives suddenly wandered into the Oschersleben area from further afield. Meanwhile, the trail for my wife’s maternal side, “Rapien”, and its spelling variations, has disappeared in 1801 in the Mecklenburg area.

We tried the usual ways to get past these road blocks:

• writing to living relatives in Germany but getting little to no helpful response,
• contacting unknown “Renneckendorfs/Rapiens” we found in the online telephone book for Germany with some minor success - but no documentation to prove familial connections.
• naturally we joined Ancestry.ca, as well as MyHeritgae.com, Verwandt.de, Wer-Kennt-Wen, and only found some minor success for these two particular surnames.
• LDS searches of their microfiche and online records to no avail.
• We then contracted a professional genealogist in Germany who subcontracted local archivists etc. to track down some of our documents. This has had the most success to date, but even these professionals are now finding the trail going cold and understandably do not wish to spend a lot of time on expensive and fruitless speculative searches among area churches and archives. They do not know where to look next and our oral history was used up long ago.
•  We even plotted an electronic map with the clusters of current living Renneckendorfs in Germany against those we found documents for going back to the 1790’s; and against those we found via Google’s book searches dating back to the 1300’s. Why? To find possible towns they lived in so we could narrow down what churches/archives to seek out. The pattern? Three
  clusters, with the oldest Renneckendorf’s (1300’s) living around Schwerin and perhaps
  slowly migrating to Oschersleben (1790s – 1900), and then perhaps migrating to the Dortmund/Ruhr area for today (1950’s – 2011). Interesting exercise but unhelpful to our team of research professionals.

Germany seems to have unique issues which make genealogical searches more challenging than other countries:

• a history of wars and religious strife going back to at least Charlemagne, which resulted in migrations of refugees and wholesale destruction of records over the centuries.
• A late nationalization so that secular records only go back to 1871.
• Perhaps, a national guilt complex related to World War Two which makes today’s residents understandably reluctant to share their family trees or documents.
•  Then we find a surprisingly strict set of Privacy laws which restrict record searches to direct-line blood relatives of those born before the 1890’s – much further back than other countries
  require.

So … might any of you have tips you can share regarding legal and cost-effective work-a-rounds to re-find our lost and cold trails among the many churches … or suggest some other sets of documents and their locations that might have survived the many upheavals to some degree?

Cheers and thank you everyone - Bo Renneckendorf & Janice Wright