Hi Paul!
Tomas here, the lead game designer of Mutant: Year Zero. Very cool to read your thoughts and feedback! Some short comments:
Regarding social conflict – the system is not primarily designed for PVP social conflicts, but primarily for PC vs NPC conflicts. I do agree that the fact that the defender doesn’t get to roll a defense roll makes PVP social conflicts a little awkward – the initiative is very important in conflicts, and doesn’t really make sense in PVP social conflicts where there is no clear “aggressor”.
Let me explain briefly why the conflict system overall is designed the way it is. Most of my previous games (such as Svavelvinter, here’s a link to a quickstart in English: http://frialigan.se/wp-content/uploads/2013/06/Svavelvinter_quick-start_set.zip) have opposed rolls as the basic game mechanism. Not so in Mutant: Year Zero. Why? Because getting a “defense roll” against attacks gives you a sense of security. I didn’t want that in Mutant: Year Zero. When someone pulls a gun at you and fires, you can’t dodge the bullet. You need to be the guy who fires first.
In social conflicts PC vs NPC, this generally works, but in PVP, it doesn’t always make sense. In these cases, if you do feel a dice roll is in order, I do think an opposed roll (like a close combat attack that is defended against, p 84) would make the most sense.