Requiring 50% to be saved is a good move, I might steal that. I think I might also do a "match" to a Roth IRA when they're older and actually earning taxable income.
My mom never tied allowance to chores, we were just expected to do chores. The problem with tying them together is that at some point the kid will just opt out and you have no leverage. I had a bank account but we were never diligent about deposits so saving was harder for me as a young adult.