I have made a list with 500 Chengyu with German definitions. You can find the list here: http://www.skritter.com/vocab/list?list=161565733
It's taken out from the book: Sprichtwörtliche Redensarten
500 häufige Redewendungen
von Manfred W. Frühauf, 2010
and I got permission from the author and the publishing house to publish this list - so no copyright issue.
You'll find the explanation of the meaning in the definition and a more literal translation in the mnemonics.
The chengyus are not coming from a frequency list, but I checked with some Chinese people and they told me, that all of them are commonly known chengyus.
Warning: if you study this list, it may add quite a number of not so commonly used characters to your study list, so be careful.
Happy Learning!