Would she be able to form a weave wearing the collar whose express use would be to cause someone to remove it? I don't think so, mainly because it seems to be the intent that causes mental difficulty. Add to that the fact that your channeling abilities are not really under your control while you are collared, and it seems to me that Compulsion is out of the question. She could have Compelled Nynaeve, Elayne or Egwene otherwise to escape without entering Tel'Aran'Rhiod or by entering it and doing it in the world of dreams.

It seems that the collar plants an inhibition in the wearers' mind that is encapsulated in what a collar is and how it feels. The first property is that it enforces control over certain characterstics involved with channeling and the second property is that you can't try to remove it without being punished.

Would Moghedien be able to hold off the nausea channeling without a sul'dam's permission would trigger in order to complete a Skimming weave or to Comel someone? The limitations set on Moghedien were quite problematic to deal with: she couldn't channel, couldn't escape and couldn't try to undo the collar. It's very hard to work around these limitations, even with freedom of movement and the ability to enter T'A'R.