The One and the Three

If so, could Frodo (or whoever), if he put on the ring, boss around Galadriel?

i doubt it very much, but only because frodo wasn't a powerful wizard ruler or of high elven blood. but if we were to say that Galadriel/Gandalf/Elrond were to recive the ring , wear and master it, they would have controll over the lesser two. i find it more likly that if one of these three had taken the ring to themselves they would have given their orginal ring to another and been able to control it's power proxy so to speak, rather then keep both the ruleing ring and one to the three. as an added bouns they would be able to order the nazugal around, so taking care of sauron wouldn't be hard as it sounds, providing that there was time to fully master the ring before sauron could make a counter attack