Good to see Adam again, even if it is only a dream. The 'charge' is perfectly fair – Hiro has been running around using his powers for personal gain. Sylar is the best example of that – Hiro could have stopped Sylar before he became immortal and he selfishly kept Charlie alive, letting Sylar go to continue killing. Never liked Charlie and she was utterly pointless, except to Hiro, and Hiro let dozens more die. Hiro got off his path about two years ago and it no longer the hero he likes to believe he is.
Claire is so rude to Sylar – he's practically family, he was even a Petrelli for a while. Which means that hot kiss was practically incest. Sylar has a good point – they do have a lot in common, in the future Claire was a killer too. She's quite a hypocrite. Liked Sylar pretending to be Gretchen – that was shockingly subtle for Sylar, powers on the fritz or not. Who knew Sylar would be such a cupid?
So Hiro is the other character that was supposed to die – to be honest, he hasn't been anything but comic relief since season 1. He's adorable and I've always liked him but he isn't remotely important to the story.
Vanessa was the only thing keeping Samuel human – without her, he will become the monster.