On one level, it's a fair cop. I have certainly encountered every single usage listed by the writer of the document (attributed to one Jeremy Gardner) during my 14 years in Brussels, particularly in the last six years when my office has been in the heart of the EU quarter. (The document omits "cocktail", which in Brussels means a reception where wine and snacks are served, but never actual cocktails.)
But on the other hand, I find myself dissatisfied with some of the analysis. One or two of the listed usages are clearly wrong - for instance, I'll agree that "punctually" or "opportunity" should never be used as illustrated. However, what is the problem with using "badge" to mean a security pass, even if it is not stuck or sewn onto your clothing? And "comitology" and "cabinet" are certainly terms of art which are taught to every student of EU structures and actually have Wikipedia articles (linked); they may not be in the OED but they clearly have legitimacy through widespread use. This is not just the way the EU crowd write, it is the way they talk, and on one level this looks like an attempt to constrain the natural development of linguistic communication to arbitrary rules set by people who are not in the conversation.
In fairness, this document was intended for a fairly small audience - those translators who are drafting material for readers outside the Eurobubble. Considered as a guide to making EU documents comprehensible to native speakers of English (and those who use it professionally as a second language outside the EU context) it is probably a very useful piece of work. But my anarchist soul wishes it had been presented as a dictionary of the Brussels dialect of English, rather than a finger-wagging set of admonitions about right and wrong usage.