RIP, always sad to read of a suicide.
I wouldn't consider trolling and abuse as the same thing.
Trolling is silly behavior and sarcastic jibes etc, basically harmless.
Abuse is vile swearing threats and so forth.
The former is a wind up merchant, the latter is criminal behavior.
I've never understood the term 'internet bullying' either, unless they are people you already know trying to bully you on the web, as well as in person.
Oh, and I think there's nothing wrong with saying you don't like something about a model, or airing your views. Adults should be able to handle a little bit of negativity. Nothing is learnt from constant praise, of which much is fake. Constructive criticism helps you improve. No doubt some girls would consider it an attack if you critique their nail polish. I have no time for diva drama queens.