I think you’re underestimating the intelligence of average people. There’s definitely a lack of knowledge, but average people are plenty smart to invent everything you’ve listed. It just takes time and is an iterative process.

Definitely yes, but like all philosophies your understanding will develop as you age and your perspective changes.

Consider the book Happy by Deren Brown. It’s a great summary of Ancient philosophies and then a good ‘entry level’ introduction to Stoicism.