When you say "One big difference, however, is that citizens are free to purchase property in any of the districts in any of the AW worlds and are not restricted as to the number (subject to having the necessary funds of course)." I suppose you mean patrons. Citizens can only have one small house. You could perhaps also mention that citizens are not able to add threads within boards, but patrons are, and patrons are able to go and add threads on other members' place (it can be very helpful for the poor citizens, but a scaring feature, also).
Thank you.