] What do you all think? Do you see signs of this addiction/attraction to 'violence' as Tave suggests?

Possibly, depending on which definition you use (from Webster's on-line dictionary):

Main Entry: vi·o·lence
Pronunciation: 'vI-l&n(t)s, 'vI-&-
Function: noun
Date: 14th century
1 a : exertion of physical force so as to injure or abuse (as in effecting illegal entry into a house) b : an instance of violent treatment or procedure
2 : injury by or as if by distortion, infringement, or profanation : OUTRAGE
3 a : intense, turbulent, or furious and often destructive action or force b : vehement feeling or expression : FERVOR; also : an instance of such action or feeling c : a clashing or jarring quality : DISCORDANCE
4 : undue alteration (as of wording or sense in editing a text)

#3 seems to be the violence Marianne could be "addiction to". However, it seems to me that Marianne is just so accustomed to behaving in a way she believes is expected of a passionate and unreserved person, she's having a hard time changing. I think it's just her teenager habits, and will change with time and exertion (do I sound like Elinor?). I think "Drama Queen" is a good modern tag for her! I don't see any violence in her actions, other than violent / exaggerated reactions and emotions.