its also now the first time in modern history that instead of the prosecutor having to prove your guilt (all he has to do is show the pics lol) you have to prove your innocence!
I'm not sure you have got that right. It is necessary first for the prosecution to prove that the image comes within the meaning of "extreme pornographic image" as defined in s64(2), then, if it does, you can produce as your defence, evidence that one of the matters mentioned in s66(2) applies. You may have other defences as well.

There have always been pornography laws in England - cf Lady Chatterley's Lover. Look what they did to Oscar Wilde. Do you remember the prosecution of the producers of The Romans in Britain?

Not to seem complacent, I think the judiciary will probably apply this new legislation with a degree of caution and prudence. Otherwise, many of our avatars would come within s64(6)(b), and I don't think that's what's intended.