You know, I don't really mind people linking items in non-trade chanels. The problem is when they spam the non-trade channels with "WTS [Purple Gem][Green Gem][Yellow Gem][Blue Gem][Rainbow Gem][Thick Leather][Heavy Leather][Light Leather][Rock][Dagger of Annoyance] pst best offer". That and immature nonsense like the "anol spam" WoW has, though that's a problem no matter what channel it's in.
My first post to trade chat when I first log in will be, "WTS [Thunderfury, Blessed Blade of the Windseeker], serious offers only."
(I swear I'm not a troll, I barely ever talk in public channels, but SOMEONE's gotta do it ;P)
But as to Darastrix's concerns, yeah those are all valid worries IMO. I think it will really, really depend on how the flow of Cyrodiil PvP actually goes at launch. I'm guessing the first month or two is going to be really hectic, as players are going to be forming their guilds and alliances, leveling like madmen, and the race for the very first Emperor is going to make it such that keeps are under attack 24/7. Or, we'll get one big zerg PvP guild that has formed pre-launch that just decimates the zone before the "regular" guilds can catch up.
But after the initial PvP frenzy dies down, and more people reach max level, and get a handle on the gameplay and combat mechanics, then we'll have to see how things settle.
It's two months old, but here is an interesting interview Shoddycast did with Nick Konkle, where he spends some time talking about AvA stuff.
https://www.youtube.com/watch?v=llYBrAi95d8
He seemed pretty confident that they were going to have the taking and holding of keeps flow in a pretty natural, fun fashion. One detail he mentions is that there are A LOT of keeps. So IMO the pace of taking new ones, and being able to defend them all, might happen much slower than we imagine.
But it's really all speculation right now, because so much of it depends on how the game is actually balanced at max level, how much damage players do relative to health pools, how strong healing is relative to damage, how long it takes to respawn/run back after a death. How long it actually takes to break down a wall with siege equipment, how long it takes to repair that same wall, etc.
One fear I have is: Ebonheart Pact is slightly favored in polls right now, although not by much...but those polls are taking place on gaming sites and forums, places where people are following the game and have been for months pre-launch. But there are tons of TES players that aren't on websites all the time, who just pick it up at launch. Skyrim is in the EP. Morrowind is in the EP. And Oblivion took place in Cyrodiil. So there might be a pretty huge influx of TES players going to that alliance at launch.
Now, this is a really speculative guess of course, but if in fact we do see faction imbalance like that at the start of the game, ZOS will take steps to increase the length of holding time for keeps, making it easier for a smaller force to hold them for longer, making an overall monopoly of the zone more difficult. Which will be good for merchants; the slower that keeps change hands, the better for business, and every alliance wants at least one fortified keep to sell their wares.
Although on the PvP side of things, everyone and their mothers' pimps are going to WANT that Emperor title, so there can't be constant stalemates either.
However it does work out, I imagine it won't be a huge deal for merchants in the first couple months, because it's going to take a while for the market to get itself set up anyway. You need a large pool of merchants at top end before prices will stabilize, and you also need a large pool of high-end buyers to have cash on hand for those things. Obviously it's gonna be chaotic in the beginning, but game markets tend to level out by the first six months.