I'll re-post this because it was added in later.breithauptclan wrote:
Edit: And most importantly, how do you convince the people that you are playing with that your answers to those questions are the 'correct' way to do a sunder action?
A lot of people are going to see that Strike doesn't target items generally and especially not attended items.
Aside from repeatedly telling people that you are right and that 'it must work the way I want', what rules are you going to use to actually support your position?
Personally I would say that the following clause of the Adjudicating the Rules section would apply:
∙If you're not sure what action a task uses, look for the most similar basic action. If you don't find one, make up an undefined action and add any necessary traits (usually attack, concentrate, manipulate, or move).
It's a pretty easy step from "Strike Target Creature" to "Strike Target Object". Sure it's deeply at the GM's discretion, but I would say it is well supported by the rules.