I have an intense dislike of the character Kes (because I think she is sickly sweet) but I have nothing personally against the actress Jennifer Lien. There used to be one poster who was very upset over Lien's "brutal firing" but I suspect that Lien got over her dismissal a great deal quicker than that member did - at least I hope she did otherwise I would say she had emotional issues that needed to be redress.
I can't say all that much about Jennifer's acting ability. I don't think she really had enough skill to pull the character of Kes off as well as a more experience actress would have but this was her first major acting role so I can give her a little leanway. I thought she was OK in American History X which is the only other role I have seen her in.
I don't care if Lien had a drug problem or not. Plenty of people in the business have substance issues and to me it is a non-issue if she did. I don't care about actors personal lives , all the matters to me is how they come across on the screen.
All that said I must admit I found Lien's voice annoying and I can't understand why other people liked her voice so much.