How exactly do elemental weapons and IED work?

[AzureGladiator]

Anyone know maby if weapons with innate elemental damage can proc on striking, like psychicals?

Yes. As long as the damage is coming from the weapon, it should proc on striking regardless of element.

[Gamdol]

On striking is based on the skills you're using, but if the skill procs on striking you can proc it with an elemental base.