I have something for you which fits your description of:
"has to have interesting and useful topics. It has to have some thought provoking and controversial topics. It has to have trolls, and even petulant veterans who have been there too long."
Have a look at www.heise.de
it is mostly IT/Tech centric news with attached discussion, quite lively.
and specially to not the miss the Telepolis subsection. www.heise.de/tp
It features articles from independent writers about a various topics political and non-political. I am sure you will be called a sock puppet in no time.