k-troop, I'll make this simple for you.
I would support penalizing a player in all instances when a ball moves (dictionary). The player should then replace the ball in all instances. Completely takes judgment out of it - whether the ball "oscillates" or "moves" (RoG), there's a penalty, and the player has to pick it up and put it back down.
That would make the rule relatively simple, consistent, and clear.
I don't care if they'd effectively be trying to put the ball back in exactly the same spot. Nor do I care if they gain 2mm (just an example) of "movement" because they can't exactly replace the ball - that movement has effectively cost them a stroke already. "Replacing the ball" falls under the same "to the best of your ability" levels as we already use it - when we lift our ball from the putting green, etc. Only egregious errors are punished even with HD cameras (i.e. like that guy on the European Tour who routinely gained an inch or so by marking to the side, then putting his ball down in front).
I agree with you that would be the simplest solution. I still think it's a fiction to simply go through the motions to "replace" it, but it is simpler. That would be easy for all to follow.
It doesn't eliminate the sheer luck factor when a ball simply moves while a player is addressing it (say a gust of wind happens at the same moment). In those cases you either unfairly penalize a player, or you have to use judgment to assess why the ball moved. But that probably happens only very, very rarely--and lots of unlucky (and potentially unfair) things can happen on a golf course.