And once again you're blurring definitions. By the definition you answered "yes" to above how can you claim that you wouldn't let children be raised in an abnormal family? Parents that get children at 45 are "abnormal" by the definition you agreed to, they're 'not the norm'. But I'm sure you wouldn't say that they shouldn't be allowed to raise children.
Either you're using abnormal just as 'not the norm', in which case you can't use it as a reason why someone shouldn't be allowed to do something. Or you're using abnormal as a description of something immoral. Please specify when you say "abnormal", and if it's the latter of those you need a reasoning to support that it is in fact immoral, because being 'outside the norm' surely isn't that.
No there's not a massive movement for incest in Europe. What gave you that idea?
The closest thing I could find regarding Holland based on what you described was this:
http://www.newgon.com/wiki/Age_of_Consent
Is this what you're talking about? If so this doesn't seem to support the decay of society in parallel with acceptance of homosexuality, but rather quite the opposite imo.