New Spring
Ch. 16 - The Deeps

Lan assumes the oneness ko'di in a barn:

"Seating himself cross-legged on a bale of straw, hes assumed the ko'di and floated in calm emptiness, one with the bale beneath him, the stable, the scabbarded sworn folded behind him. He could 'feel' the horses, cropping at their mangers, and the flies buzzing in corners. They were all part of him. Especially the sword."

Soon after, he is attacked (same chapter):

"As Lan moved forward to meet his attackers, he heard the bar drop inside with a muffled thud. Relief was distant. He floated in ko'di, one with the sword that came smoothly out of it's scabbard."

Elsewhere in new spring it talks about Lan being able to sense people behind him and even while he's sleeping. You and I can't fathom being that alert because we are like domesticated dogs and they are wolves. People who live in constant readiness to fight, a state of being that hasn't been prevalent in the world for a thousand years, seems hard to understand.

Same thing with Galad. He and Gawyn can't channel, get over it. They're excellent swordsmen, trained by the best in the known world (pre-seanchan). Just because channeling runs in your family doesn't mean everyone gets it. Moiraine had 3 sisters, and only she could channel. She is as predisposed as any of the other 3 because they were all fathered by a Damodred as well. I know Galad has Tigraine's genes as well, and his half-brother Rand can channel as can his half-sister Elayne. But if they were going to play that kind of role in the novel, I think they would have shown it already.