i wouldn't shake any keg. its gonna make it foamy and then eventually ruin your head retention. i think the maybe storing it upside down might be a decent idea, but a pain for serving.
i've never actually paid any attention to the cloudiness of my hefes from the keg. never noticed too much or too little yeast in suspension. it just seems to work itself out. i think really [though a yeast whisperer would have to confirm this] that the hefe yeast doesn't flocculate so really it stays in suspension fairly indefinitely. what i can say i've noticed is that my hefes taste awesome, but they definitely don't last all that long. 6 weeks and the flavors start to muddle.