Here's the details on #2.

This LA Time article from 2021 gives a list of all the statistics that have been "debunked" by the "fact-checkers".

Column: Debunking Trump’s ‘Big Lie,’ scholars and statistics show the facts don’t add up

— Joe Biden won more votes than Trump even though he carried far fewer counties. (A meaningless statistic. Biden cleaned up in big cities while Trump carried more rural areas and, thus, more counties.)

— Trump won more bellwether counties. (Another meaningless statistic. Bellwethers reflect past performance and don’t determine election outcomes.)

— There was a big difference between votes that were counted early and those that were counted late. (That doesn’t indicate fraud. Republicans were more likely to vote on election day and more Democrats mailed in their ballots. So they were tabulated at different times.)

— Differences between voting patterns in 2016 and 2020 suggest voting irregularities. (Election results aren’t stamped out on an assembly line. Things invariably change from one campaign to the next.)

— More votes were cast in 2020 than there are voters. (It didn’t happen. That falsehood grew out of a faulty analysis that took the turnout rate for eligible voters — those 18 and older — and applied it to the smaller number of registered voters.)

— Machines run by Dominion Voting Systems switched votes from Trump to Biden. (A statistical analysis shows no significant difference in Biden’s performance in counties using Dominion machines compared to those using other means to tabulate their ballots. The software and voting machine company has sued the right-wing propaganda networks Newsmax and One America News, among others, for defamation for widely promoting the misinformation.)

— Fulton County, Georgia, which takes in the Atlanta area, and Allegheny County, home to Pittsburgh, were major centers of fraud involving absentee ballots. (Not so. Grimmer and his colleagues found there was nothing unusual about Biden’s absentee ballot haul in those counties relative to his performance in neighboring counties.)

— Turnout was unusually high in Democratic-leaning counties in a number of important battleground states where massive fraud is alleged. (There was no fraud and no unusual surge in turnout.)

https://www.latimes.com/politics/story/2021-08-17/trump-big-lie-experts-debunk-voting-fraud-claims

Archived link - https://archive.ph/uwWgv

Also some guy on 4chan analyized the ratios between candidates in the mail-in ballots over time which should remain constant since theyre all shuffled together. But as time went on the ratio moved more in favor of Biden suggesting that they were stuffing the ballot box after they knew how many theyd need

https://votepatternanalysis.substack.com/p/voting-anomalies-2020

This is as close to definitive proof youre going to get w statistical analysis. Theres a ton of other weird shit but it but hard to draw conclusions from it beyond 'this election was weird' whereas this shows deliberate coordination along with quantitative adjustments showing the effects were significant