>As I see it, you'd need Probe rather than Read Surface Thoughts to do
>what you describe above; does a sleeping person _have_ Surface Thoughts
>to Read? Also, a dreamer need not be a psion; a non-psion won't be able
>to shield, dreaming or not, and under the standard rules, a psion is
>automatically shielding all the time once s/he learns how, even when
>sleeping.

True, but I was not being terribly specific about ruleset. Second, based on X-Men and Star Trek (and other fictons), I assume non-psionic characters can develop a skill at shielding or at least annoying attempts to read them. Sleeping while wearing a psishield helmet will be very uncomfortable. And a trained adept may be automatically shielding when asleep, but that defense cannot be as good as a shield that they can modify as it is attacked. And I also assume that epilepsy can be triggered by teeping, with effects hitting the teeper AT LEAST as hard as the epileptic, who will have much more experience with the disorder than the teep will. 

>Question at large: Should I explicitly state that a psion cannot be the
>target of a dreamwalk, except voluntarily? Or should I leave it as the
>default assumption based on the "always shielded" rule?

Voluntarily or if the dreamwalker can successfully bypass their defenses. 

>Your comment about therapy and 'Manchurian Candidates' is definitely
>well-taken (and therapy would undoubtedly be a function performed by a
>Tavrchedl' dreamwalker); there's also education (but not physical
>training). I'll discuss those possibilities as well in the next
>revision.

I hope it helps. I always enjoy psi in a game. I added various abilities to my game long ago, based on various games, books, and movies. Articles about psi usually interest me, but over time, I've become more critical as too many were just kewel 'new' ideas that weren't really new or all that cool. 

I like Asimovs (mentioned in B5, should be self-explanatory). 

Nodes (a novel I read; the psi imprints his personality and powers on a victim who then acts in his interests with a weaker version of his powers.Nasty things to do to PCs!)

I invented telegraphy in the 80s (teeping the opponents next actions from body language, nerves, and surface thoughts, without concentration, while in melee). 

Directed teke - instead of levitating things away from you, teke things you touch, or yourself - lift heavy items as if you are superstrong, leap like a Jedi, or express it as a third arm, like Gil the Arm. 

Sapience - tap the racial memory to 'know' anything  - IF you can find someone who knows it. Madness can fool them into thinking they know it, so when you find them...

Maybe this will give you some ideas? Because I still see dreamwalking as little more than a background flavor article, not something PCs will cue in on. If I used it as the explanation for a Manchurian Candidate situation, how many players would see the difference between dreamwalking, dominate, or any other mind control technique? The difference would fly over their heads. Dreamwalking allowing the changes to avoid seeming to caused by domination or other psionic means would make the players feel I lied to them when they find out he was programmed that way, even if I showed them the passage in the article that makes it clear that dreamwalking can program responses that seem natural and not installed psionically. They'd hare off looking for nanites or cranial screw-top brain surgery.