An option for the effect to stay on the objects permanently as it returns to normal after a while

Yep definitely will add. For now i did 30 secounds to not set RP servers in chaos

Perhaps all NPCs infected become neutral to one another and alert all that are infected when an enemy presence is near? Would kind of remind me of The Flood. I know this might be difficult to do with as many NPC bases there are nowadays, VJ, DRG, Zbase ect.

Yep this will be difficult but i alr had that idea.
I surely can find a solution to many NPC bases to set hostilities but not for changing in to corrupted. Im afraid that only NPCs that can use weapons (that is not originated from there base) will infect others

add corruption goo.

Make it where the longer you're infected the more unstable it becomes

Maybe corrupted objects can corrupt other stuff it comes in contact with

Make the bones of the object/entity go all over the place. If it only has one bone, then do nothing. 'Cause we need a 'reasonable' amount of corruption so the game won't break in a bad way.

A trail like effect when the swep is active ether that or footprints nothing useful just cool looking

World-Corruption creates a mist of corruption that spreads across the map its spread being stopped if the source is destroyed with only things on the ground getting corrupted

you cant equip any other weapons

make it where the corrupted npc's don't attack you if you are corrupted.

I have a few suggestions for the addon. The first would be that a corrupted person can pass through corrupted props. The second would be that corrupted people do not take damage from firearms or other means. However, there should be weapons and machines that can counteract the infection to maintain balance. And last but not least, people or props that you have corrupted that you can absorb into yourself to strengthen yourself and maybe learn a few powers, such as a power where you bring people into a corrupted world or traps that you could set up.