about the whole line of Wizards passing the wand and initiative thing, ready an action won't work, since you can only perform one action with a readied action, delay should work fine though.
As far as the using the wand, I think I would rule that objects can only be used a number of times in a round as if 1 person was performing the action, instead of multiple users. Meaning a Wand could only be used once since it requires a standard action, a door could be both opened and closed, but not opened again regardless if one person is doing it or two people. An Item could be dropped any number of times, but could only be picked up twice since doing so is a move action. The object has used up all it's "actions" for that round. It makes since and is simple, and maintains the feel of simultainity? without being overly complicated. It may not be RAW, but they also didn't used to have rules for how far you could fall in a single round either.
As far as the using the wand, I think I would rule that objects can only be used a number of times in a round as if 1 person was performing the action, instead of multiple users. Meaning a Wand could only be used once since it requires a standard action, a door could be both opened and closed, but not opened again regardless if one person is doing it or two people. An Item could be dropped any number of times, but could only be picked up twice since doing so is a move action. The object has used up all it's "actions" for that round. It makes since and is simple, and maintains the feel of simultainity? without being overly complicated. It may not be RAW, but they also didn't used to have rules for how far you could fall in a single round either.