> Voting officials should be selected by sortition at all levels
It's actually a pretty hard job, so I don't think that that's very realistic. I've worked as voting officer a few times in Canada, and it's a ~15 hour shift with maybe an hour of breaks total (or if you're unlucky, zero breaks), you need to be quite organized since there's so much paper, and it's quite stressful due to the volume of voters (some of whom tend to be quite angry).
The actual procedures are fairly simple, but you need to do them ~300 times in a day, without making any mistakes, while being rushed by the long lines. Anybody on HN could probably handle this (it's only a single 3-hour training course), but it's probably beyond what a substantial portion of the population is capable of, so sortition probably wouldn't lead to great results.
> Allowing self-selection can allow for collusion or a biased pool of election workers and judges, especially in cities/towns with an established single-party patronage bureaucracy.
In Canada, any candidate can send up to 2 people to each ballot booth to observe the procedures and ensure that all the rules are correctly followed, and most serious contenders tend to send at least 1 person to each polling place. So this should help to prevent collusion in most cases.