[b]Bran, Butcher's Boy, Arya, Joffrey:[/b]

Oh right right, god season one feels like decades ago.

I don't know if we knew what to make of the assassin. I thought Petyr hired it, gave him a sword which he stole from Tyrion?

Well Arya's direwolf will run off, she'll probably be reunited later. In terms of Sansa's, it doesn't have to die so soon, since Joffrey won't tell his mother about the incident until I assume Sansa blabs about it to Ned and Cersei. Arya is smart enough not to say anything or could say something to insult Joffrey later on, in regards to the bite.

I love Syrio, I refuse to believe he's dead. but if Joffrey is more useful with a sword, who else but Syrio to teach him? Robert would be useless, as would Tyrion. Jamie is an offer but I assume he'd be busy most of the time?

[b]Ned:[/b]

Ned does need to be more careful when talking to Joffrey and I think it was the lack of respect and credibility that Ned saw in Joffrey, that really sealed his fate. If Ned plays his cards right, he could have Ned bending to his will, to an extent if it means his family is safe.

[b]Sansa:[/b] 

Sansa isn't much of a conversationalist. While Arya has a tongue on her, it must be better than someone who is bland.

I doubt Joffrey would miss her much if she was taken away from the city.

As far as her use, she could probably be taken to the Wall where Jon is.

[b]Petyr:[/b]

Seeing Ned spared would surely throw a wrench into Petyr's plans. After all, he's been working hard to get Ned into trouble. If Ned lives, he's game has to change or he has to try to keep the upper hand. If he manages to get to Cat before Petyr does, Petyr could be more of a present enemy sooner, rather than later.

[b]Tywin, Tyrion & Jamie:[/b]

I'd like to note I am not a fan of Shae or that one girl Robb marries, so if excluded them or off'ed them, I'd be fine.

As far as the Battle of Blackwater goes, it would be useful to have Joffrey not shitting his pants and fighting by Tyrion's side. It would ruffle Tywin's feathers no doubt. He can't control his godson and Cersei has lost her touch by then, surely. It would bond Tyrion and Joffrey even more and yes, piss Cersei off and probably put her on suicide watch.

If Robb still marches onward to get his father free, I am sure Jamie and Tywin would make themselves scarce to deal with that headache. And then there'd be the issue of unrest in the city I'm sure. The people don't want a war to start for petty reasons, they could easily turn on the castle and demand more food, coin, etc.