I posted about this on your Moddb page, looking for some help with 2 idea's:
Zombi u/Dark Souls like Spawn system: When Player dies instead of quick loading they spawn as a new Stalker and can retrieve any mission items are useful stuff from their previous Character.
Grenades and Bullets affected by Anomalies: I don't know if this is even possible in the Engine, like throwing a grenade into a Whirligig, it get's caught in the anomalies field and when it explodes it sends out fragments charged by the anomaly (same with Bullets, fire one into anomaly and the Anomaly changes it's trajectory and alters it's properties).
This one would probably be simpler to do:
Helicopters for fast travel if you're Military/Duty/Ecologist or Mercenary, like a helicopter on the roof of the Scientist bunker in Yantar with dialogue options to move to areas you can't get to on foot.
getting to grips with modding Stalker and just seeing whats possible, if someone could point me in the right direction to try these ideas it'd be much appreciated.