He was - Time resumed before Sylar grabbed the sword. Notice that his mother had been frozen in place as she fell. Time resumed as hiro swung the sword and she continued to fall to the floor.

I'll have to watch that again. I thought Sylar moved his eyes before Hiro swung. Did Hiro stop "stopping" time, or did Sylar somehow become immune. Interesting question.

There were 2 separate paintings. 1 of peter lying dead or dying in front of the clock - this was the initially missing panel.

Which, again, while coming true, wasn't all it was meant to be.

"the other was a cheerleader [thought to be claire] lying dead with sylar standing over her"

No, it was claire on the steps with a shadow looming over her. This is where Peter ran into her and confronted Sylar.

"Yes but i think Isaac's plan did involve Hiro traveling to the future [that future] and back again, for some reason. He told sylar he was going to 'show them how to kill you' - Given that he wasn't going to survive the encounter he had to have already planned something out - ie: the comic book pages or the sketchbook.

Perhaps. I guess it really all depends on whether Sylar survives in the last episode or not. Didn't Hiro say something about it not being time to kill Sylar yet? I don't recall if they mentioned a timeframe or not. Technically speaking, if all Hiro does is stab Sylar, then Sylar should be able to heal (unless the sword is left in him. Maybe the broken end breaks off again inside him, leading everyone to believe he's dead?

Peter died - they didn't know Claire would / could resurrect him
The dead cheerleader is jackie - not claire. We cant know if at any point this was to be claire.
Hiro and Ando were there - just not at the same time.

It appears we're on the same track here, but I don't get the reference on the last one. I'll go back and look for the scene I was talking about as well.