1. "And so I learned that we hadn’t been paying payroll taxes for almost 3 years – a particularly painful thing given I believe in taxes as a means of giving back to society." It's weird and manipulative to throw in how much you believe in giving back to society here. You majorly screwed up oversight of how investment money was being spent to not notice the difference in financials given no taxes were being paid!
"This hurt even more because I’d been paying myself one of the lowest salaries on the team to maximize our runway and support our mission." Again, you're the founder. If you're going to make that statement, at least include that you have a much larger equity stake in the company - you're not sacrificing yourself completely!
2. "Mistake 3: Not being explicit about hacks" should be re-written, "Being Dishonest." Cloaking the language as "hacks" and again referencing PG to make your behavior acceptable - (he says it's ok, it's just really a grey area!)
3. "Mistake 7: Telling a half-truth" should be called "lying." If you still think it's a half-truth, you have NOT learned your lesson. It's not "rule bending." Everyone knows that when you say you dropped out of Harvard, the assumption is that you were some form of degree earning student. Seriously, it wasn't a half-truth if the people you're talking to were assuming something else - it was a lie.
Lastly, NOWHERE do I see remorse for the lives of your employees who you laid off. These people trusted and believed in you, and you let them down. Did these people find new jobs? Did you help them find new jobs? How did you structure their layoff packages? Are any still struggling? Were you able to support their next career moves in some way if not monetarily? Not really mentioned, which suggests you don't really care. You're much more focused on you.