First, a simple question. Wards only affect astrally active characters, correct? That is the way I read it. Astrally active means full astral, assensing and dual natured for these purposes.

Second question and the one that really needs some chewing. If a character leaves his body on an astral task and his body is moved into a warded space, does the character still have to fight the ward to get through? Does the ward impede the character's ability to find his body? Or does the location of the body provide a 'key' through the ward?

Yes, wards are mana barriers, not physical. They can exist on the physical plane (still *mana*, though), the astral, or both (IIRC).

AFAIK, the body isn't astral, so it can be moved inside fine. The projecting form has to deal with the ward as normal. As for *finding* the body, I can't recall seeing rules on that either way, with or without wards.

Right. Wards might have anchors and bounds on the physical plane, but they're effectively walls on the astral plane.

If the owner of the ward allows the mage's astral form through, then no the mage does not need to fight the ward to get through. If the owner does not allow the mage's astral form though, it must fight to get through. If the body is moved outside the ward just as the mage's astral form enters the ward, the mage will have to fight his way out again. The body being on the other side of the ward doesn't provide any extenuating circumstances.

In SR3 there was an easy way around this. When a mage's astral form was disrupted (full stun track) it would snap back to the body immediately, wherever that was. Therefore a mage would wear an electric shock bracelet set to deliver 10S on a timer set to a few minutes shy of Essence hours (say 7 hours 55 minutes for shapeshifters; 5 hours 55 minutes for (meta)humans with no 'ware, etc.) If the astral journey went sour and the astral form got trapped within a barrier, or digging through the earth, or hiding from Threats, etc. when the time was up the mage would receive the shock and snap back to the body. Unconscious but better than Essence zero and dead. If the astral journey was fine, the bracelet would be taken off. I don't know if this mechanic still applies in SR4. If so, just Stunbolt yourself. It's the magic equivalent of pinching yourself to wake up from a dream.

While convenient, that's all kinds of unsatisfying. How does stun get from the inert body, to the astral form, and then the form snaps back? Messy.

Probably via the silvery cord. A mage or group could go on an astral quest to the metaplanes. The astral form there could receive damage. The mage's friends back on the physical plane could heal that damage using the local inert body (though doing so did raise the TN of the astral quest).

The "While you were out..." sidebar in the BBB:
If the magician’s physical body is moved while she is out, she will not feel anything. When she attempts to return to her body, however, she will discover it gone. The magician must attempt to find her body before her allowed astral projection time runs out, or she will die. See Astral Tracking for more information.
(and mana barriers increase the threshold for Astral Tracking)

Nice, thanks Sengir.