This is an excellent post and does a great job also highlighting possible pitfalls in most stoic approaches. The danger of turning apathetic is an inherent danger and one I have noticed myself years ago when I first pursued a similar philosophy, ataraxia. Eventually I abandoned ataraxia because it was too self-centric for me and, while definitely almost blissfully enjoyable at times, too apathetic.
Yet, those who practice stoicism on a daily basis should have less problems with keeping the dial tuned in a rational matter. I know I sometimes steer away from the middle ground and that not necessarily because I don't spend enough time with (daily) self-introspection but IMHO because I don't journal. Which when I do I find definitely one of the strongest and most valuable exercises of all.
I am not sure our mindsets are something we (partially) inherit but our close ones are definitely cultural influences which will define much of our future thinking and approaches to life.