Joining the enemy usually requires some sort of deal to be worked out ahead of time so that the victorious enemy doesn’t roll over you too. 

So retreating is usually the move. 

There sort of is one already, the winter town, which has a population of ~50,000 in autumn and winter, and ~10,000 in spring and summer. 

So you wouldn’t need to build a city, just expand the existing town. 

I don’t think it’s suggested that at all. Stannis pick up ~4000 Northmen by basically looking through the sofa cushions, Roose has ~2,000 Northmen “allies” outside of his own Frey/Bolton forces, plus you have the Dustin/Ryswell contingent who held back, plus you have Wyman Manderly’s secret army hiding on the White Knife. 

The North’s normal military strength is ~35,000 men. Robb took only 18,000 south with him, because he was in a hurry to save Ned. That leaves 17,000 men who never went to war. 

We don’t have a good deal of information about this. Here’s what we know:

“The fact that the Andals forged iron has been taken by some as proof that the Seven guided them—that the Smith himself taught them this art—and so do the holy texts teach. But the Rhoynar were already an advanced civilization at this time, and they too knew of iron, so it takes only the study of a map to realize that the earliest Andals must have had contact with the Rhoynar. The Darkwash and the Noyne lay directly in the path of the Andals’ migration, and there are remnants of Rhoynish outposts in Andalos, according to the Norvoshi historian Doro Golathis. And it would not be the first time that men learned of the working of iron from the Rhoynar; it is said that the Valyrians learned the art from them as well, although the Valyrians eventually surpassed them.”

“…The Rhoynar brought considerable wealth with them; their artisans, metalworkers, and stonemasons brought skills far in advance of those achieved by their Westerosi counterparts, and their armorers were soon producing swords and spears and suits of scale and plate no Westerosi smith could hope to match.“

So we know the Rhoynar had really well-developed iron and steel-working and had had it for a long time. And we know that they were making scale and plate which was much better than the Andals could make (who I guess were using chain?). Which is interesting, because whenever we see Rhoynar armor before Nymeria or indeed in Dorne, it’s all scale and not plate.

As for a timeline of technology, it’s a bit confusing. We know the First Men only had bronze, we know the Andals learned iron (as opposed to steel) from the Rhoynar, but Andal invaders are described as having “steel swords and iron ringmail,” which suggests an intermediate stage of development). That quote suggests that plate armor only came to Westeros 700 years ago, but we also hear that the Marcher castles were built to “guard the borders of the stormlands against…the steel-clad minions of the Kings of the Reach from the west.” 

But technology is uneven, so transfers could come from many places. For example, we know that the Valyrian and Ghiscari Empires had steel plate (since Xanda Qo of the Summer Isle built bows to penetrate plate armor during the Slavers’ Wars) more than 5,000 years ago. 

Not really. Joining the NW means somehow crossing entire warzones and marching or sailing thousands of years, and that takes food a lot of people don’t have to begin with. 

I wouldn’t say they run out of food, it’s more that Yoren is rationing because those supplies are supposed to last them all the way up to Castle Black. 

I lean mild Ricardian; Richard seems to have been an effective administrator and, while he certainly was a Plantagent power politician, he was certainly subjected to a lot of Tudor propaganda that tried to pin pretty much every murder in 14th century England on him. 

As for whether GRRM is a Ricardian, it’s kind of complicated. On the one hand, Tyrion is depicted very sympathetically, but as someone who is hated because of his disability (and for a long time, Ricardians argued his disabilities were a Tudor invention, which turned out to be only semi-true). On the other hand, while the play in “Mercy” depicts a Shakespearean propaganda play, Tyrion did do some of the stuff he’s blamed for. 

It’s possible, she would have been about 53. But given that we never hear of her during Robert’s minority after Steffon’s death, I’m guessing she wasn’t around by this point. 

GRRM has an even closer parallel to the Wild Geese in the Company of the Rose, founded by men and women from the North who refused to accept Torrhen Stark’s submission to House Targaryen.