According to RAW, the Discipline check difficulty is only based on silhouette of the object being thrown.... A silhouette 0 object would be difficulty 0 or 1 ? My guess would be it's a difficulty of 1.
Also, if a stormtrooper hides at medium range behind a crate that I lift and hit him with using the Move Force power, I would not need to trigger the range upgrade since the target is at engaged range with the object that I throw.
I find it odd that you have a double check condition for the Move Force power... If I throw a silhouette 1 object at a target, I need to trigger the Strength upgrade once and I need to succeed a PP difficulty Discipline check, both because of size....
My take is that it would have made a lot more sense if the Discipline check would have been made like a normal ranged attack, difficulty based on distance between Force User and Target, while the Force Power check would need the necessary upgrades of Strength and Range.