Lot of what you said is true. Good advice many people should follow.
Just, paradoxical reactions are a bit more complex, took me decades to figure out. Nyquil has me curled in a ball, twitching, spasming uncontrollably. Nodoze sent me into a violent rage, up all night. Lot of meds, make most sleepy, but me, rush of energy, awake all night. Antipsychotics meant to calm me, instead out of control anger. Benadryl means eyes wide, pulse racing.
It had nothing to do with dosage, plasma levels, titration. There are just some people bizarrely hypersensitive to meds, who have the bizarre 1% side effects the other 99% doesn’t get.
But for that 99%, everything you said is true, again good advice and info.