It's good to see you, too.
I expect Ms. Knox's case regarding her callunia conviction to be successful at the ECHR. The circumstances of her interrogations are pretty much text book violations, and I will be very surprised if the ECHR doesn't take that view as well.
As for Guede being retried on the basis of new evidence, no, I do not think that anyone involved in Guede's conviction will try that on. To amount to "new evidence", it typically has to be something that was (a) not known at the time of trial and (b) not available by way of reasonable diligence to have been known at the time of trial. There is a reasonable diligence component, and that does not extend to evidence to which a party was wilfully blind or evidence that a party deliberately ignored. In an application to adduce "new evidence", the party seeking to adduce the evidence has to show that the "new evidence" is not something that they were aware of previously or that they should have been aware of previously by the exercise of reasonable diligence. In the circumstances of this case, I do not think that either Guede or the prosecution could legitimately make such a claim, and I do not think that either of them will go anywhere near that putative semen stain. Everyone has known about the putative semen sample for years, and neither Guede nor the prosecution wanted it tested (or wanted the results of any testing to be made public if the prosecution did actually test it and suppressed that fact).
So, it seems to me that neither Guede nor the prosecution will claim that it is "new evidence" at this stage.
As to whether Maresca continues the other civil actions, you may be right, and he may be foolish enough to go there, but I tend to doubt it. The optics will be very bad. Plus, for him it's always been about how much money he can get out of this case, and there is very little money to be gained in pursuing the remaining claims. He stands to gain next to nothing even if the remaining (ludicrous) civil claims are successful. His only financial payoff would ever have come as his percentage of the multi-million euro judgments he hoped to be able to collect upon in relation to the civil side of the murder charges. With all hope of that payoff gone now, I think he will cut his losses.
As always, though, one never knows, and it will be interesting to see what happens next.