Move Object discussion and possible changes
It seems to me the “magic bullet” problem is solved simply by using the Move Light Object ability of the Use the Force skill. If you use MO (or MLO) to move something that is 5 kg or under, it falls into this particular use. That limits it to dealing 1d6 damage. So, you can’t toss a marble “at super accelerated speeds” to deal 10d6 damage. If you move a marble and toss it at someone, it only does 1d6. Period.
Anything from 5 kg up to “medium” size, does 2d6, anything of large size does 4d6, and so on. This is exactly the damage from MO. The object moved really should determine the damage dealt, otherwise there wouldn’t be a limit on MLO, would there?