I agree, though it would seem more likely that she was involved than she wasn't - rather a lot of circumstantial evidence, suspicious behaviour and some disputed DNA evidence on the murder weapon. Plenty of lies too which appear rather dubious regardless of the poor innocent girl I terrogatrd by angry foreign police angle - every account she's come up with has been highly dubious and inconsistent. It's not sufficient to convict her so the court must find her not guilty but it's enough to presume there is a good chance she was somehow involved in the murder.
No it's not, it is enough to presume that a terrified and naive young girl was in a situation she could not deal with and that she taken advantage of by a corrupt police investigation, because that is what the evidence suggests.
People are under the assumption that the Italian justice system is in any way comparable to our own. The prosecution can make up whatever scenarios or claims they want, it is up to the defence to show they are not true. The prosecution didn't even have to justify many of the claims made about Knox or Sollecito, let alone offer proof. The satanic ritual nonsense for example.
In any case, whatever the truth, the presumption should be geared toward someone's innocence not their guilt, something that Knox and Sollecito where never given the benefit of.