Josep,
As far as Move being "broken" in terms of what can be affected, the largest determining factor is what the GM makes available for the Force user to affect. If there's no Silhouette 4 objects within range to throw, then the PC's not going to be able to use all those Strength Upgrades, are they? As the GM, you're the one in charge of setting up the scene, so if you don't want the PC to be flinging around corvettes and capital ships like they were toys, then simply don't include objects of that size in the encounter design. So if you as the GM are constantly putting such large objects around for the PC to make use of, then that's on you, not the design team.
Also, FFG has routinely demonstrated that they are not limiting themselves to "canon," and there are plenty of instances in the EU/Legends of objects far bigger than Silhouette 4 being affected by the Force, and not just in the Force Unleashed games. Whether you like those instances or not, they exist, and are something that needs to be accounted for.
Plus, with the FaD Beta Updates, any and all Upgrades can be activated multiple times by default, with Move's Strength Upgrade being specifically changed to say "can be activated multiple times." So even removing one of the Strength Upgrades doesn't "fix" your particular problem, it merely delays it until the PC can pick up Force Rating 2 or better and thus have a chance of triggering that Strength Upgrade multiple times.