If there's one thing I wouldn't want to mess with is the IRS. I have a few acquaintances getting trouble with it and that sends me a signal, just don't fuck with them. Have him check out this youtube channel by Caleb Hammer, it's entertaining and some ridiculous examples on personal finance.
😄 It's always nice to retire early, debt free and you can do whatever you want with the time. I hope you get to do it soon!