Well this article (in dutch) has the following table:
|Further ease of abortion||Euthanasia|
|Adoption for gays and lesbians|
The full analysis (PDF) can be downloaded at the end of the article, it is a survey done last year on about 1000 people in Belgium.
Okay, it could be better but then it can always be better. Clearly a majority of Belgians are quite progressive.
This is why I'm not too worried about any religious education that my daughter might be getting when she'll be at a catholic school, chances are most of her teachers won't even believe in a god ...