Would it be possible to add a flag to DestroyItem, so we can choose if it runs its unequip script? Be pretty handy.

This can be scripted in the DestroyScript for the item.

You could do something like this:
Then, in the UnequipScript, simply test for the #nounequip cprop. I recommend returning 1 to allow the item to be unequipped, even if it's also being destroyed.

I also recommend you make it a #-prefixed cprop so that accidental settings of the prop don't eat up save file space. However, if you have situations where you KNOW a certain item should NEVER run an Unequipscript, you could use a permanent cprop, instead (so that you don't need to use two different ones)