If you want to wait for regen, burn it to 51% on scout bar, wait for everyone to regen, then start dumping. bars wont regen at all this way. Then just get everyone to burn max xtals if they can, and phase 2 is actually quite achievable in under an hour with enough people. Seen it done many times already
Well phase 2 still regens the Attk/Assassin bar even when Scouting the last 50%, not sure about the first phase but I'd say it's the same.
This is a good idea but as its been said everyone is always at a different regen, a lot of people don't read CA or CC before hitting, (should be the first thing you do when coming online) so would be hard to coordinate. Especially in an item clan where no one knows each other.