Okay, so I have several different ideas about several different things. First is about the Taim/Demandred thing. There are so many things that point to Taim as being Demandred. Here is some proof:

1.) Taim is a man about 35 years old. That means he could have been channeling for 15 years at least. No man lasts that long under the taint on saidin without going mad, unless he has ties to the Dark One.

2.) When Taim was freed, he was taken away by stealth and two sisters are dead. What could get through a mess of Aes Sedai, Warders, and soldiers, save for Shadowspawn? That could mean anything from Gray Men to gholams. And if Shadowspawn freed Taim, it leads to the question, why? Would the Dark One risk such a maneuver unless Taim really was one of his upper minions?

3.) Lews Therin, in Rand's mind, said, Sammael and Demandred hated me, whatever honors I gave them. The more honors, the worse the hate, until they sold their souls and went over. Demandred especially. When Rand gave the Asha'man their name, he pinned a sword and Dragon on Taim's collar, and the man became stone. He never wore the sword and Dragon again after that, a sign that he despised the honor beyond all bounds.

4.) Lews Therin's reactions around Taim could stem from a part of Rand recognizing Taim for Demandred, and he tells himself that through Lews Therin's voice, even if he does not truly agree (and if you're wondering what I mean by that, there's a great web page dedicated to the Rand al'Thor/LTT integration you should most definitely read, especially if you were disappointed with CoS).

5.) Sammael indicated that Demandred enjoyed using proxies. Taim could be using Rand as a proxy Rand with all the power out in the open, while Taim twists the Asha'man to his intents.

6.) Taim mentions so-called Aes Sedai. Judging from Lanfear's reaction to Rand calling her Aes Sedai in tGH, the Forsake all seem to hold today's Aes Sedai in complete contempt. Any many of this day and Age, who had once been captured by Aes Sedai, would not hold contempt for them.

7.) Amy's message of a man holding a dagger to Rand's throat without his seeing it very subtly hints at Taim being a great, unknown threat.