What a well written article!
I hope you didn't waste it on some of the other crab boards...
Being German born and having migrated only in my 30s I'm still very much in contact with people over there, and a good number of them know what I'm doing, so sometimes the talk comes to topics like adult sites, dialers, etc. PLUS: the adult part of the internet is actually openly discussed in many of the mainstream computer and entertainment magazines (unlike here in OZ)!
So I can only support the views of this article from my own experience!
Specially the option for different billing systems is an important one; CEN used to be the first program who had a link to European style processing (incl. 'Überweisungen' for Germans, with easy to understand German instructions), and I believe that's one of the reasons CEN always converted well for me! And SMS billing is really the next big thing in Europe, and already far more used then you'd probably imagine!
I don't think that with all sites it's as important to translate the tours, specially not the ones relying on graphics and content snippets, but it would certainly help with any text heavy tour and sites which offer something special which needs explaining...
If your website needs a German translation , which is fluent and well worded, contact me for a quote! george|at|TropicHeat.com