All dead voters should be disenfranchised, they had their day, unless a mail-in ballot was postmarked on or before the official date of death. Non-US citizens, out, even if they become official days or weeks from now. Not yet, out. The jailed, nah, they should not have citizen influence until they are freed.
Unsigned voter ballots is a tough one. I vote we accept them, unless the voter is dead or a Non-US citizen as described above, signatures through the mail is sketchy. All duplicates should, by rule, be thrown out, the duplicate and the duplicated, to be clear. Also, votes that come from US citizens in the wrong state should be tossed, stick to your state. Weird ballots should be axed for sure, ballots that just look weird, everyone knows what a weird ballot looks like.
Get on with it, fold up the ballot machines, they are from last century, we need to enable the glowvote. Vote from our glowdevices, vote with the touch of an app. Ditch the U.S. mail, register all eligible voters automatically and accurately, close all the polling places. The truth is, polling places have no real place in the future of voting. Such a hassle.