I understand better why my impression after reading TOM was so much that the city would fall. Elayne doesn't know Shadowspawn can't use Gateways, and Birgitte's AOL knowledge of that has probably faded. Having her expect the invasion will come over the borders (likely the northern one) doesn't exactly show her in a good light.

Beefing up the borders of Andor? Ouch, that means between the troops Elayne is bringing to Merrilor and the soldiers she sent to reinforce the borders, that's a whole lot of Andoran soldiers who are nowhere near Caemlyn anymore, and scattered along the borders or on their way there, making the logistics of gathering them back to Caemlyn very fast quite complicated. Reinforcing the southern border, if Elayne sent armies there, is another potentially bad scenario considering that Roedran may very well decide the best way to keep his new gained control of the nobility is to throw them into an attack to seize the chunk of southern Andor they always wanted. Stupid of him, with the Seanchan on his borders, but Roedran isn't know for his cleverness. Many expect Demandred is behind Roedran, but there are rebel Aes Sedai ambassadors at his court, fairly likely to include BA. Very bizarre Roedran happened to find a rare military treatise only scholars like AS (and Mat!) know about. Very bizarre also that he got at the right time exactly the idea that would have countered Egwene's use of the Band to force the Rebels to keep moving north, something both the Shadow and the Hall were desperate to stop. And all of a sudden, Roedran made an offer to the Band that was noted as much too clever for him... It's with the declaration of the Law of War and her executive order they'd Travel soon that Egwene unknowingly defeated these plans (from either Sheriam/Aran'gar or the Hall, or both) to remove from the equation the excuse she was using to move north.

The Waygate situation is a very good example of miscommunication among the Light (why I admit I'm quite puzzled as to why Rand didn't destroy the Waygate in Caemlyn while he had the chance, and if he did destroy it what happened for it to be re-opened. Alas, we don't know for sure if the leaf "keys" are interchangeable or Waygate-specific, for instance if you could pick one from a strategically useless Waygate and place it on another strategically important one after Loial's visit). The issue of the Shadow using the Waygates has been long known, but by too few. Moiraine didn't pass the information to Siuan, it appears, or it was part of her letters the BA managed to destroy (many of Moiraine's communications passed through Sheriam...). Siuan might have been able to get a few Waygates closed, and at least raise awareness of all rulers to the problems, and negotiate with the Ogier. Rand's strategy to attempt to keep from the Shadow that he was closing the Waygates seems to have backfired a bit. It's very possible the Shadow found out nonetheless - Rand wasn't exactly discreet with his interest in the locations of Waygate, and it may bode badly for the Light if the Shadow knew and chose in turn to let Rand believe he was succesful, while they followed behind Loial to undo his work where they could. Verin - another who knew, with Alanna - seems to have figured out the full magnitude of the disaster re: the Ways when an army of 100,000 suddenly used a Waygate (or Portal Stone) to come attack Rand at the Tairen manor and Rand revealed that the Forsaken could not make Shadowspawn Travel. Unless she already knew this, which I somehow doubt is BA-level of knowledge - the Forsaken are too secretive and especially about the limitations, she must have realized then and there that the Ways were no plan B of the Chosen when they didn't want to open large Gateways for Shadowspawn until the Dreadlords were in the open to do this for them, and that the locations of Portal Stones/Waygates would be of massive strategic importance in the LB. She then figured out how the Shadow intended to invade Andor - from inside Caemlyn itself. That may even be what triggered her departure from Rand's side, the realization time had run out and she had to act. Another possible factor is that it's when Rand sent his emissary with his offer to the AS re: Asha'man, but it doesn't sound like Verin knew how deeply infiltrated the BT was, otherwise it's quite unexplainable of her not to have warned in person/writing Egwene. Very weird, considering how much efforts she made to destroy the Shadow within the Tower.

So it looks more and more like the "mistake by Elayne" scenario for Caemlyn, even though it's one of those mistakes that may proved a good thing in the end (except if you happen to be poor Joe-the-fruit-seller from Caemlyn, that is). Elayne's recent power-grabbing may well strain things at Merrilor. It may not have been easy to convince the nations to go to Andor's rescue instead of sending their forces to protect their own cities, or to smooth things if Egwene/Logain decide to send huge groups of AS to Caemlyn's defense (the nations will all want their share of channelers, most likely... the Borderlands too are under attack, the others will realize all their cities are just as much under threat as Caemlyn. Why should Andor-Caihrien be prioritized? Because Elayne is Aes Sedai and tied to Rand as the soon-to-be Queen/consort of Tear, for instance, knows? Some rulers may very well raised those questions.

Because of the departures of many troops, the Shadow will have an easier time conquering the city (though the Band of the Red Hand will likely do big damages... in both senses as they'll likely manage to seize the dragons, but the enemy is inside the city...), but the scenario where most of the armies of Andor would have still been all around the city and suffer massive losses before channellers can come will likely be avoided. The Light is very likely to lose the city, but the strength of Andor will still be saved. It's the Band that perhaps stands a chance to end like its forerunner of the same name, buying time with Kinswomen to evacuate the parts of the city more distant from the Waygate by making dear every the advance of Shadowspawn through the city before they're overwhelmed and end in a blaze of glory. That would be a shock, most of the Band ending this way at the beginning of TG, but if Jordan intended to give the Light a very meaningful defeat/setback and give it overtones of Manetheren's end, that would be a way to do it. The channellers can join the battle at any time (alas, the Dreadlords at the BT are far more likely to join it first) if the Shadow were to move the Dreamspike to the city as soon as the takeover/slaughter of what's left of lightsiders at the BT is over, the conditions for a Manetheren style "last stand" in the city would be there. The Shadow also knows about Merrilor, obviously, which isn't good either. Demandred will no doubt have counted in his strategy on a very likely return of some forces from there.

Another worrying matter is the suspected extra "Talisman of Growing" in Elayne's stockpile in the palace. The Shadow isn't privy to Aviendha's revelations to Elayne about some of the ter'angreal there, but if Demandred or Moridin were to get access to that stockpile and figure out what this ter'angreal does, all of Rand's plan to block all Waygates (all those not nearby stedding, as many Ogier decided to only guard them, and they should be easily overwhelmed by Shadospawn, but only where the Shadow finds any strategic value in securing a specific Waygate.) may go down the drain.