More important than lack of voter fraud is proving to the population a lack of voter fraud.

This. A voting system and it security must be understandable to the average people. You can not do that with electronic voting. (Even if electronic voting can be done securely.)

I'm sure you could even let every voter verify that their vote has been registered correctly.

Edit: But as a comment somewhere else in the tree noted ,,And if it could tell you that then a third party could force you to reveal that you voted "right" as agreed before.`` - I guess everything's trade-offs.