It's workable, whether or not it's sensible
"snuff, beheading videos, hate speech, political propaganda?...Total BS. Filters do not work; ask any teenager."
But you can't be sent directly to jail for snuff/beheading/hate speech/propaganda (well, unless you're sufficiently brown and silly to convince a paranoid jury that you've got the videos because you're an Evil Terrorist). The point about filtering CP websites is that it makes it very hard for anyone caught with CP images to claim that they got them by mistake...
"Besides, who would be the authority to decide what goes in the list and what doesn't, who keeps it up-to-date?"
In the UK, this list is kept and supplied to ISPs by the Internet Watch Foundation. It's paid for by ISPs and maintained by civilian analysts with police training. I imagine this list or something similar would be used in the pan-European scheme.