Ivashanko

I think Renly has to go after Tywin first. The Starks with their presumptions of separatism are no real threat to Renly's bases of support, but Tywin is. Renly takes King's Landing and fights it out with the Lannister armies. The North withdraws, fortifies, and leaves its options open. Admittedly it is not the best plan ever, but it is workable given the situation. Robb cannot stay north of the Neck without losing the support of many of his vassals: the Riverlanders for obvious reasons and presumably many of the Northern lords because Robb swore an oath of overlordship and cannot casually break it. His retreating also destroys any chance the Vale declares for him. Robb also cannot declare for either Stannis or Renly until he knows which one will win their personal game of thrones. If he declares for one and that one loses it is a disaster. If he declares for the Baratheon, regardless of who wins, he effectively declares for Renly. Stannis would never forgive him. He needs to remain a credible threat in the field and wait for things in the south to finish up. The reason this plan failed wasn't because of anything any southern army did, but rather because Robb's capital fell to Theon's reavers. The second Winterfell was taken Robb's enemies began to stir.

Given the metahistorical view the average public has of Knightly Orders, I strongly suspect GRRM won't be kind to the rearming of the Faith. But... eh. This world is very different from the one we inhabited, all those many years ago. This world is more tolerant. It is more unified and connected, which goes a long way to explain why it is more tolerant. And it is, if anything, significantly harder on the smalfolk. It might not be a bad idea for there to be a counterweight to the nobility, to have some group, somewhere, working within the confines of the system to strip the illusions off those who abuse their power. But, as I said, there's no way this doesn't end poorly. GRRM's foreshadowing has been pretty clear.

I must be misremembering, wasn't Rob's plan to keep Tywin occupied in the north so the Baratheons' could crush the Lannisters in the south? That's not the worst plan in the world. Tywin would be forced to flee back to his territory and the Baratheons would have no choice but to invade, which would give the North time to prepare and perhaps to make peace.

I am willing to bet a lot of money that they'll make more than two seasons. I think Stannis is a believer in the books, but he's not a fanatic. He is pragmatic- he believes in the Lord of Light because that God has shown his power quite clearly on many occasions. I don't think pragmatism would make him burn his daughter though. The only occasion where Stannis would burn his daughter and have it be fitting for the character/justifiable within the moral rules Stannis seems to live by would be if burning his daughter if that was the only way to keep the White Walkers from succeeding (perhaps not overall, but in a crucial battle). Most importantly, that sacrifice would have to work- if it did not stop the White Walkers then he's just another failed fanatic, but if he succeeds then the audience has to wrestle with whether or not the price was worth it. Alternatively, another follower could burn the princess in order to save Stannis' army, but the sacrifice was not done with Stannis' consent or knowledge.

We've gotten to the point where Game of Thrones is almost certainly going to pull at least a partial Full Metal Alchemist- since the TV has caught up to the book's story, it looks like the two plots will entirely diverge. I wouldn't take anything you see on the show as being certain to happen in the books anymore.