RE: Training during PCT
You will lose strength because you've got less androgens floating around. You will lose size because the muscles will deflate a little bit. This will happen no matter what you do when you stop a cycle. However, this will happen either before or just into PCT and is not a loss of muscle per se.
Lifting with less intensity for a while will not necessarily lose muscle. I've rehabbed muscle injuries for 6months+ and when I came back had not lost any strength.
My answer to your original question is much like actin. I tend to drop weight, reps, sets by 20% from the cycle intensity (which itself is perhaps 10% higher than off-cycle intensity). Frankly in the post cycle depression that's about all I can motivate myself to do.