I've always found the American justice system to be terribly flawed. Who in his right mind thinks that 12 random incompetent individuals should be giving a verdict on a case?
Makes a lot more sense then having a judge make the choice.
1 Judge systems invariably end up with the powerful eaislly beign able to get away with things and those of "lower classes" and certain circumstances getting screwed because they aren't ever judged by their piers, but instead some Judge who probably has never been lower class, and likely spends all his time with high brow people. The kind of person who won't understand a crime someone committed in the past or something someone else did while desperate.
Jury's allow for many different perspectives to be brought so that more perspectives can be weighted and a better outcome can be had... additionally it's a lot harder to bribe anonymous jurors then it is one well known judge.
The problem with the jury syste,, is that jury members really aren't qualified to properly analize evidence and reach a verdict. Screening processes don't take into account things like education or intelligence, and smart people often manage to find a way out of jury duty, leading juries to be made up of the lowest of the low. Regular people are also probably less likely to be objective, and will let their biases take control of them. I mean, not long ago, a jury (always all white) would convict a black man of whatever he was accused of, regardless of the evidence presented.
Not to mention that trying a case has become like a sort of circus in your country. Lawyers mainly just put on shows to try to make the jury side with their client, and they do whatever it takes, even exploiting biases and other irrational beliefs. This makes for nice material for court room dramas on TV, but it really shouldn't happen in reality. A judge is much more competent at making a fair decision, and your 'bribing the judge' argument isn't as big as the 'bedazzling the jury' argument.
1) Neither are judges. Did you see the Judge in the Hotz vs Sony case claim that Hotz had to "retrieve all the emails he sent out with the sony code on it." Judges aren't and can't be experts on everything, the only thing they are experts on are the law... which is kinda hard, when the law is only a structural component. With the Judge guiding a trial, there is no loss at having a Jury decide the outcome.
2) Not really. Everyone has biases and by limiting judement to basically one type of group... what you end up with is one bias ruling over all. See for example, france where the Rich and Powerful can basically get away with anything.
3) Again, how would this of been different with the racist white judge who was put in power by the racist white politicians who passed the Jim Crow laws? Once black jurymen got in the jury things got fairer... however, if there weren't jury trials... the racism via Judges who worked with racist politicians would of lasted a lot longer. Kinda like... well France again.
As for the second part...
that's why it doesn't happen in reality! That's what judges are for... to disallow BS evidence and experts that don't pass the test. If you think the American Court room system actually works like court room dramas... you've got another thing coming.
4) What about... bedazzling a judge? Judges aren't immune to this sort of thing afterall, Judges aren't experts on forensic evidence, they need it all explained to them by the same experts. Nearly everything that needs to be explained to a jury has to be explained to a judge.