a) I've taken more time than you to look into evidence in this thread
Yeah, but you need to do it well. The video you complained about has ~15 fact checks. You only query 7 in #470. Of those seven:
(1) You are wrong. Trump claimed he got football restarted, and the league denied it. According to that evidence, he was therefore bullshitting at best.
(2) You are partially wrong. There's a question mark over the validity of Biden's claim, but Trump was lying to say Biden plans to scrap private insurance for 180 million.
(3) You are wrong. Biden did not state opposition to a China travel ban. You have unfairly magicked up your own rationalisation to argue he did.
(4) You are wrong. Biden was technically being fact-checked not Trump, and Biden was right. Although I agree in a wider context this may not constitute a Trump lie.
(5) Contentious: the fact-checker is correct given the justifications provided - but it could be argued with other data
(6) Contentious: the fact-checker is correct given the justifications provided - but it could be argued with other data
(7) You are wrong: Trump misrepresented the situation and made an unsupported implication of electoral fraud. It was wrong/misleading, so effectively a lie.
So of your seven complaints, four times you were wrong, and the other three are varying degrees of dubious. Add in the ones you decided to not challenge, that gives the fact checker 12/15 correct and three where their analysis was defended, albeit could be disputed with other evidence.
What you can also take away from this is that fact checking can be hard and the risk of error exists. I don't like binary "lie/truth" because I think it forces ideas of certainty that don't exist, and some of the above examples demonstrate that problem because they require complex analysis with competing data. But in and of itself, that fact check video appears to be mostly sound. Your analysis of it, however, is not.