Unless you're a hacker, and you like hacking on stuff, then by all means, read through all the warnings and please do consider doing similar to what OP did, it's a lot of fun and you'll learn a lot!
Eh, as a hacker who has wasted time on a lot of dumb stuff I would encourage people to not follow absolutely every obsession you have and think of the opportunity costs of new projects you take on.
As a hacker who never wasted a single minute of my life, yet did a lot of dumb stuff, I'd say your mindset is what's getting in your way, not the amount of dumb stuff you've done :)
There is a good reason why most home battery storage solutions are based on LFP batteries and not NMC as used in vapes.
LFP is a much safer chemistry that can withstand higher temperatures and won’t bust into thermal runaway like NMC.