Charbon - good post at 00:43:46.
I agree that inferences, rather than evidence, seem to be taking over some parts of discussion. I don't remember any particular stress on his being either sweet or monogamous; I do remember his admitting to being a deceitful, manipulative liar.
I've just seen a commentary on the BBC, and their expert was attaching importance of avoiding an appeal over the admissibility/inadmissibility and a potential retrial. Just think of the impact on the family if that had happened?
I think also that this thread shows why it was the right decision to exclude: despite patient explanation by many posters, there was still a strident insistence that motive was relevant to this case, and an inability to grasp the difference between intent and motive. This tends to support the view that the information would indeed have wrongly influenced the Jury (I mean wrongly in the sense of attaching weight to motive, which is not required for a safe conviction, though it is logically and emotionally satisfying).
Finally charbon: I agree, on the basis of what has happened so far, that there are wider factors which may have failed Joanna, in terms of tolerance of porn. And there is no definitive answer to your question about where the prosecution was in all this.
But I have a guess - remember the aftermath of Baby P, and why anonymity was seemingly inexplicably kept in place. It was because further charges, and convictions, followed. There has been a hint in the press that more action may happen on this. So it seems they have taken the most serious charge first, and then will examine the others. This has several important advantages; all the things in relation to this trial and avoiding appeal that have been explained in this thread, separate and sounder basis for potential future charges, and IMHO the very important emotional reason of sparing Joanna's family from sitting through detailed evidence on porn charges if everything was taken together. It would have made the trial much longer, and much more distressing.