No, it doesn't have much more ambiguous categories. AFAICT it only covers video, only covers porn, has a regulatory process involving notices and dialogue, excludes websites with low traffic, exempts any material that wouldn't get an 18 certificate (i.e. it can't apply to simple nudity or fetishes), is open to legal appeal.
There's no guarantee you won't get idiots running it. But that's no more an argument against this than it is against town planning or state education. In fact, it's less of an argument - since we'll never be rid of idiots, this sounds like a less risky place to put them. However, I'm finding it hard to see how there is an unacceptable risk of catching innocent websites in this. "It happened with not very dramatic consequences in another case that wasn't really comparable" isn't really an explanation. Have you actually read the Bill? Where, specifically, is it that you think it falls down?