I agree that Semirhage was much more believable after she'd collared Rand. I remember clutching my book in horror when I first read that scene, certain that Semirhage was going to force Rand to kill Min, and feeling every second of Rand's horrified desperation. Using his own hands and his own Power, it would have snapped his (already fragile) sanity even without the severing of the Warder bond. Given a dungeon and a few weeks to work, she probably could have had him do it even without the collar. But I digress, I wasn't disappointed in Semirhage completely, just in her response to her captivity. Where was the Semirhage who, in the AoL, managed to frighten her jailers into smuggling her to safety? She didn't have saidar then either.

But I suppose, like all the Forsaken, she underestimates the modern people of Randland. She might actually have been arrogant enough to assume she couldn't be captured, which would be idiotic, considering Rand's track record with the other Forsaken. Again, disappointing.