Wow, thanks for this comment man, I really appreciate !
As you said about artists trying to hide the real purpose of the character, the meanings of the shapes squares, triangles etc are the obvious ones, meaning if you use them, the viewer will easily understand the story.
But these principles can be bent following your story. Check at Bobby Chiu's paintings, he has some really rounded evil characters. In the end it all comes down to your story and how you want to communicate it.
Another analogy with colors for exemple where you can see green as peaceful, harmonious and calming color (miyazaki's movies for exemple) but it can be used as an oppressive one as well, like in the Matrix (when they get in the Matrice the color key becomes greenish). Thanks for your comment man ! Cheers !
I agree! The thrill starts when what was cute and cuddly turns to be evil or badass! Haha. There are really a lot of things that could be a cue to revealing a character but the element of surprise can steal the spotlight sometimes. Cheers!! @alcy