First of all, we have coffee places, just like in the US. But as far as I know, we tend not to bring our laptop along. I certainly never did it and I never saw it either. I must admit I'd rather read a book then take my laptop along...
Now, about the politics, yes it's true there where a lot of political problems concerning the separation of Belgium into 2 separate countries. Today (almost) nothing has changed. The issues the news reported about back then are still not 'solved'. It's just old news for the media and the people got tired of it so nothing happens anymore. But to give my personal opinion, there never was any problem. To me all the fuss was just to get some media attention for the elections back then and things got a bit out of control. The big problem should be between flanders and walloon, the 2 big parts of the country. But many of my colleagues are walloon and I have absolutely no problem with them at all, why should I? So my opinion about the whole issue is: it was just some publicity stunt. Sure we hear all the time there are 'issues' and flanders is giving (some politicians even call it wasting) a large sum of money to the walloon but I see it in a bigger picture. And as far as I know, that's the main issue about politics.
The last answer, the startup culture. To be honest, as I see it, there are 2 big cities with startups at the moment in flanders: Antwerp and Ghent. You also have Brussels but it's really expensive to live there, if you want to live in a 'better part' of the city. Starting up is not so hard, just get a BTW number (it's a special tax number), fill in some papers and you are working for yourself. The thing is, taxes are rather high so you tend to have less money left. Of course you have an upside too, if you should fail, you can apply for unemployment benefits and even take courses for free (they even pay you to do it in some instances). The typical startup here is different in the sense that here you don't make a web application that attracts a lot of people/investors, you make applications for clients. A group of people I worked with recently started their own little company ( http://1md.be/ ) and as you can see they follow that principle. I guess Belgium is just too small to do it the US way, it's even worse if you know websites from flanders who are immensely popular are not popular at all in walloon and the other way around. So in conclusion, I don't think we have the same startup environment as 'you guys'. If you should move only for that, I think you're in for a bit of a disappointment. Of course that's from my point of view!
Hope this answers your questions, if not let me know!