I'm not a court lawyer although I am married to a litigator. His experience of juries are they take it very seriously. Why would they be idiots?
I don't understand the comment about bias affecting the selection of juries. Juries are picked at random from the general public although certain people (including me) are permanently ineligible. The Crown and the prosecution are each allowed a limited number of peremptory challenges from the pool of jurors called on the day.
The idea that a crime victim gets to choose who hears their case is not realistic. How would that even work and would this apply to other accused. ? It also misses the point it is not "their case"- it is the Crown's case.
Would a jury with more female members be more likely to convict? I'm sure I've seen research which contradicted that.
I would very much like to know what the reason was for taking evidence in private. I don't however think that will have swayed the jury to convict.