Every time an article like this one comes out I become more and more convinced that official languages are a really bad idea.
English is going to be the common language, at least for the foreseeable future, no matter what the politicians do. As I see it, there are only two questions that politicians should be asking:
1) What languages should we make compulsory in the school system?
2) What languages should parliamentary and regulatory acts be translated into, so that each version has the same legal authority.
As far as I can tell (it’s difficult to Google on the topic), there are no standard compulsory languages in Belgian education. What languages are offered varies from school to school. This is fine, but I can see that for national unity that a policy where everyone is instructed in a basic proficiency in both Flemish (Dutch) and French would be a good goal. The problem is that English should really be taught as well, and having three languages in an already crowded curriculum would be difficult. So it seems that the current solution of offering a variety of schools and options and letting the market decide is a good one.
As for parliamentary and regulatory language, it’s really just a matter of budgeting enough money for quality translation. If you’re willing to pay for it, go for it. You do need a working language for day-to-day business, but it’s best to just leave this unofficial.
Back in my days as a diplomat, the international organization I worked for had the standard six official UN languages, but with the exception of the annual plenary meetings, all the business was in English with no translation provided. (Official documents produced at the working meetings were eventually translated into all six languages, but this was after the fact.) Arrangements could be made to provide simultaneous translation at working meetings (I’m fuzzy on who paid, the organization or the country requesting the translation), but the only times this was used was when the Chinese delegation brought in higher-level diplomats to observe the session; and when they did this, the Chinese still spoke in English; the translation was simply provided for the convenience of the larger delegation who needed help following the proceedings in English. (The only other delegation that brought in others to supplement the usual delegation at working sessions was the US, and translation was not an issue.) We once tentatively brought up a proposal to make English the official working language, but it was shot in the crib by the French. It seems the French had no problem with the unofficial arrangement (like everyone else, they didn’t want to spend money on translators), but they resisted any official language that was not French.