The question "how many users do you have" is impossible to answer, as all I can ever demonstrate is "X users used Cydia in the last Y period". As for your second question, the information I have for your average Cydia user (one that is not actively paying me money, in which case I obviously have tons of information) is purposely highly limited: I certainly do not have, for example, the "names" of devices that was included in these dumps from AntiSec (which often discloses the name of the user), or any of the other personal details that are claimed to be in the original file.
