I wondered if the show was hinting that Tyler had actually shot Alex and made it seem like a suicide-- he seemed to have pictures of the "13" people in his darkroom and took down Alex's picture as if he had taken him off his hit list.
Otherwise this final episode was really strong. I'm 37 and it really got to me. All these kids deserved better (except Bryce) despite whatever behavior/action they may have displayed or taken. They're teenagers.
I think Hannah did try to tell Jessica while she was alive, but, again... teenagers... can't expect them to communicate in the most mature ways. The Jessica rape scene and afterward were difficult to watch and I don't know what I would have done at age 16-17 if I had been in Hannah's shoes.
I can't even begin to imagine how much more hurt Hannah's poor parents are going to feel after listening to the tapes. And it makes me so damn sad that teenagers (and adults, too, but especially teenagers) can't see any other way forward with their lives and so commit suicide. It's profoundly sad in a way that is indescribable with mere words and this show really drives that home.
P.S. One concern I had throughout was that some despondent/hopeless teenager/kid will watch this series and decide to do something similar. I know the show is not a PSA, but it is in the Young Adult genre, technically, and I don't know if they showed that Hannah had other options that she just couldn't see-- yeah they showed that Clay really cared for her, but... it just wasn't enough. I'm not sure wha they could have done here to address that.