Hello /monarchy/, nationalist without a specific ideal government here. Personally, I am not a hereditary monarchist, however I realize that saying "hereditary monarchy is bad, don't do it" just makes me sound like a shill. So I'd like to discuss with the hereditary monarchists here about what you would do, or how would you set up a hereditary monarchy as such to try and make sure you ended up with the best ruler the system could provide.
When it comes to what makes a bad monarch, one aspect I suggest you look into is high functioning sociopaths. Many modern politicians and CEOs are suspected of being sociopaths, as sociopathy aids in the process of scrambling to the top of the success ladder while having no regard for the people they step on to get to the top. I personally suspect this is the cause for much of the selfish and outright abusive behavior that nobles and aristocrats subjected to their people, as well as the willingness to borrow money from Jews to advance their interests.
pic is related, it's the Voight-Kampff test from Blade Runner, a tool used to differentiate between synthetic humans (who lacked the genuine capacity for empathy) versus real humans.
How would you separate the good eggs from the bad ones?