Btw, we still have only circumstantial evidence that Taim is a darkfriend! :-)

I'm doubtful regarding the "fake seal" theory. From KoD:

 

Quote

 

“Ah, yes. The seals. Indeed, they must be found.” Moridin’s smile was almost complacent. “Only three remain, all in al’Thor’s possession. though I doubt he has them with him. They’re too susceptible to breaking, now. He will have hidden them. Direct your people to places he has been. Search them yourselves.”

 

Would Moridin lie to the other Forsaken if he knew that one of Rand's seals was a fake? ...

And additionally I doubt that the shadow has tried to retrieve the seals before. In the above quote, Moridin doesn't seem overly enthusiastic about it, and why would he explain "there are three left, all in rand's possession" if he ordered to retrieve them before?

I used to believe, too, that the attacks on Bashere's wife and on Dobraine where carried out to get the seals. But recently I looked at the timeline and realised that both attacks happended exactly after Rand revealed his plans to cleanse the Source and before the Cleansing itself. Now I'm pretty sure that it was Moridin sending (non-channeling!) darkfriends to look for the access keys.