As far as mandatory voting is concerned, how do you sell that to people? Are you going to put out advertisements and say that if people don't vote, these are the consequences? You're basically putting an even worse taste in people's mouths. You get them to associate punishment with voting. It just doesn't work for me. It's on a rights and freedoms basis.
As far as technology is concerned, you're absolutely right. There is no computer-based technology that is going to be 100% hack-proof. We can sure damn well try, but ultimately it's the people who design it. If there's an ulterior motive behind the people.... Put it this way: computers are logical and they're only as logical as the people who design them and use them. If a computer breaks, it has nothing to do with the way they're using it. It's simply something illogical has happened, period.