Our group views TTRPGs as a way to experience a story or world. I know some people like to minmax or love rules and that’s great. But for us, while all worlds have rules, if the rules don’t lend themselves toward fun or progressing the story in a manner that makes sense, then I either adjust, change or don’t enforce them. I also will mix and match rules from different systems that I’ve enjoyed.
As for what rules, you already mentioned a few. We also utilize potions as a bonus action, but I don’t limit them. I do this because they like boss fights that include big hits and having the capability to heal helps ensure I’m not unfair during a fight.
We also utilize a karma system. I give out karma during sessions for excellent role play, ingenuity, making everyone laugh and for birthdays etc. They can then use this karma to buy certain enhancements from a genie prior to encounters. Enhancements include different things such as adding +1 to a die roll, rerolling, rolling with advantage, or even a long rest (super expensive). This has helped keep people engaged and gives some combat helpers that minimizes the impact when they are on a negative rolling streak.