I believe that a wizard who successfully senses that an object is magical could try and use the dispel talent against that object. I would have the dispel talent act more like a suppression against forge weapon/armour then a permanent dispel. I would say something like 1-2 rounds per talent rank + extra time per success would be how long the dispel lasts. Anything that requires a ritual would fall into this category in my opinion.
As written the talent should allow a complete dispel of the forge weapon…but I feel that If a wizard wanted to permanently remove the bonus on a sword that has been forged, I would require a bit more study (in a non- combat setting) I would argue that the ritual of enchanting the sword requires more than just a quick dispel.
I would not allow a weaponsmith to use his steel thought to cover his items, friends or anything around him from a dispel If a wizard is targeting his sword, the sword must save. But maybe this could be a talent knack for a weapon smith in a future product

#Horrors-are-jerks