1. Yes, and not just randomly. They all get a calibration test run 80 days before an election (once the ballot is finalized and the ballot is input into the scanner) and a random sample is rechecked 30 days before election deadline, so 14 days before the ballots are in public hands.

2. All our ballots are paper, and they're all real. On Election Day, we do spot checks -- we will pull an hour's collection of a precinct, run the ticket, and hand count that sample. If there's an error, that scanner comes out of use. In 8 elections, I've never seen a scanner fail to match the sample.

3. Our County clerks and recorders report to the Secretary of State and each other. There's both a phone call with witnesses, and a fax, on election night, then the final tallies are certified by the C&R, usually within a week. The certified tallies are crosschecked by the C&R, the assistant C&R, and reps from the candidates/parties.

In my county, the scanners live in a vault. They do not have a memory card port. To my knowledge, there has never been a firmware update because there's nothing to update. They have a small display and a means to input the ballot parameters that uses the scanner itself. It's pretty close to mechanical, much closer to a punch card reader than a laptop. (This part, I have seen, but don't know the specifics. I'm not that important.)

They're effectively the same machines my academic peers have been using for decades for multiple choice tests. The form factor is slightly different, because ballots have to be larger than basic scantrons, and we have to print the text of the ballot initiative, so formatting the ballot matters. But it's the same tech we use for everything from the Iowa Test of Basic Skills to the SAT to the GREs.