You are far from silly.
As a philosophical basis for punishment, this grumpy old lawyer thinks retribution is the only structure that makes sense. But, prevention is still better.
To psychiatric tests, add:
1. Property disqualification. No-one who earns or owns more than (for the sake of argument) 10× lowest personal income (best calculated via a national minimum wage) or average wealth need apply.
2. Age restrictions. Only those between (say) 30 and 65 are eligible.