how much autopilot can one do while in a trance?

[Laurna]

In "Camber the Heretic", when Tavis comes to Camber et. al. and they develop trust for the first time, Camber explains to Tavis (who had been surprised to find himself on the floor):

"Some people, like Joram, can go to just about any level while on their feet and even functioning.  Others, like Jebediah, go completely limp when they go into trance.  I don't know whether it has to do with training, or what.  Perhaps there's a physiological difference -- rather the way different patients will respond to a Healer's sleep commands."

That is a great quote that you found. I do not remember Camber saying this, but I think it is important. I had not thought of some people going "completely limp" while in trance. That would be most inconvenient and require the Deryni to lie down before performing any form of magic that requires a deep trance. For example: Healers must go into deep trance to Heal. We see most Healers sitting at the side of the patient. I suppose if you were one of the unfortunate ones that went "Limp", you would have to lay down next to your patient and situate yourself where you can touch the wound before you went into trance. That would be most awkward.
Being a person who went limp would be unable to do things like shot and arrow and guide it to a target at the same time. They would, however be able to lie down on the ramparts wall and defend a keep by pushing enemy arrows away.
I am imagining that training and depth of trance may have a lot to do with how much control a Deryni has while in trance. I could see this being one of those skills that one would perfect over time.

[DesertRose]

I would guess that some Deryni abilities can be used either not in a trance state or in a very light trance state (the "directing arrows" example you gave), and I would think that those who go limp probably don't go limp unless they're in a fairly deep trance.

Healing trances seem to be fairly deep, and that makes sense; Healing is complicated work that requires a great deal of mental/psychic focus.

So perhaps for those Healers who might become lethargic/unconscious while in deep trance, Healer's training included teaching them how to stay upright while in Healing trance; we know, from "First Session" (Deryni Magic, pp 202-210) that Gabrilite Healer training (and it is implied, other schools) starts with learning to regulate and Heal one's own body.

[Liesel]

It certainly depends on the depth of the trance -- what Camber about said implies that -- that Joram could be on his feet an functioning at "just about any level".  I think that implies that at some levels it would be more common to be on your feet/functioning, but at other levels not.

There has been no mention anywhere of any Healer going limp in a healing trance; though it is deep it is a very focused kind of trance -- and the Healer has to do physical manipulations as well.   I would suppose that someone with healing potential who could not learn to function while at that level of trance, would not succeed as a Healer.  But with no Healer's training at all, neither Morgan, nor Duncan, nor Dhugal, seem to have any problem with it.

For that matter, Tavis, who collapsed to the floor in trance when linking with Camber in the scene from which I took that quote, was quite surprised by this -- yet he is a Healer.  So apparently going into Healing trance did not cause him to go limp, while linking with Camber in deep sharing, did.  And it was apparently the first time this happened to him or he would not have been so surprised.  So apparently he didn't originally go limp when entering Healing trance and then learn to deal with it.  It did not happen.