Just a few points. We know that Ishamael/Moridin is pretty much on the same wavelenght as the DO when it comes to the overall objective. Aside from when he was really pissed of at Rand Ishamael and presumably the DO want's Rand alive, and in one piece at least until they get to the last battle.

The rest of the forsaken may have tried to kill him but they are following their own agenda's. Note that once the DO via SH & Moridin reined in the surviving forsaken the "kill Rand plan" seems to have gone off the agenda with the exception of when he went to cleanse the Source. The hand of the DO aka SH seemed really annoyed at Semirhage for comming close to killing Rand.

If that is what the DO wants is it a stretch for Verin to use the "I'm following the DO's general orders to keep the dragon reborn alive and well for the time being" to justify a lot of her actions?

Secondly you can't betray someone who does not trust you. In order to gain someone's trust you have to be there for them in a crises. I could see Verin argueing with BA command that she needs to be close to Rand and seen to help him. That way if he survives traps etc she would be the last person he would suspect.

Put it another way. If I help you break into the White House and randsack the Preisden't office and paint some rude messages on teh wall and then help you get away scott free would you suspect that I am secretly an undercover officer of the Secret Service. I doubt it. Then when you have a genuine plan to kill the President there is every chance you will confide in me and I can tipp off the powers that be.