I've shot three different Norincos before, and something I've noticed is that every one of their triggers will take a set if you partially pull the trigger, but release the trigger without firing (noticed this the first time when I was shooting from a rest, didn't have my sight picture just right, and released the partially pulled trigger to just my aim).  Every Norinco I've ever touched does this, so I guess it's normal, but I'm wondering if anyone has taken note of it?  Any reason why it was built this way, or is that just a result of mediocre commie craftsmanship

my yugo did this you could pull the trigger to take up all the slack and "set" it then release it and then pull again when you were ready to fire without all the slack.

Hmm.  Maybe it's just a thing with SKS rifles then.  Its not really important to me either way, I was just curious what others experiences with it was.
 

If you read This article from Kifaari about the SKS trigger you will learn about positive, negative, and neutral triggers.

As you pull the trigger the Sear is sliding under the hammers cock-notch and when you let off the trigger before firing, it stays there with the force of the hammer/hammer spring keeping it from slidding back. The trigger will return all the way, but the sear is stuck halfway untill it is reset by the hammer going back with the bolt, or the trigger is pulled again.

And on a SKS the safety only blocks the trigger, right?

IIRC, yes.