Should I simplify my writing in a foreign country? As a native English speaker studying in the Netherlands, I often find myself writing (not published) English papers for a Dutch audience, and I worry I'm alienating my superiors with my writing.

I put a sample of text from a letter I wrote for an admissions committee through an array of readability tests, with Flesch-Kincaid Grade Level, SMOG Index, Automated Readability Index, Gunning Fog, and Linsear Write all  assigning it "college graduate" level. For comparison, the King James Bible averages around a fifth grade reading level, and New York Times articles typically produce a reading level around the tenth grade on the same tests.

At first glance, this is exactly how it should be. A university student submitting university documents should be writing at a university level. And yet, despite the truly incredible level of skill widely demonstrated by the Dutch people in the English language, I can't help feeling that I'm disadvantaging myself through use of constructions and vocabulary that no reasonable non-native English speaker could ever be expected to know.

Is there some merit to this? Rather than optimizing my writing for descriptiveness and articulacy, should I instead aim to be more readable by a foreign audience, at the cost of expressiveness?
Thou shalt not dumb down thy writing, but don't make it a vain exercise of style

I'm a non-native English speaker, and let me put it straight: I may write in simple English, because limited are my English writing skills, but I don't want to read simple English because I want to enrich my vocabulary and grammatical constructions. 

But whether you write for a native English speaker or not, write clearly, avoiding unnecessary verbosity just to show off your eloquence.

(And, honestly, stop wasting time using those readability tests)