Hey Satyajit321,
1. I'm not too sure I understand this question, but if you create a folder anywhere under any of the movable folders we will take that folder into consideration and it will be moved to a new Aux mailbox location during the next expansion if the main archive is over threshold.
2. The second Aux will be created once the main archive reaches the 90GB threshold again.
3. We can move data from Aux mailbox location if it reaches to the 90GB threshold, that does not occur as often. Data will move from Main archive to 2nd Aux location on the second expansion. Data can also move from Primary to 2nd Aux location if user adds data to the folders associated with that aux location. This all happens behind the scenes and you dont have to worry about this to be honest :-)
4. The main archive will constantly take in new content if you have configured your retention policies correctly. We dont block the main archive location if there is ghosted content in the main archive.