1st rule! "For every coin that has been deposited in the bank, you get 1% interest on it once per week, with the increase being put on only durring the weekend so Saturday and Sunday are the only times that the interest for that week can be put on. After reaching 1 million zenni, you no longer get interest." Loving the fact that interest gets cut off after 1 million!
However... i have a mild dislike for the new interest o.O Yes i see the reasons why it'd be so low, the money systems on the other sites got a bit crazy ^^ But 1% is a bit extreme i think... It sort of makes the idea of a bank account seem like more trouble than its worth. Seeing as how its limited to weekends... and a whole mess of other things.
I have a bit of a suggestion on this though, my idea comes from what you guys did with Meditations. Put the interest rate on a sliding scale. Lower amounts get a higer interest rate, which slowly drops off to 0% at 1 million Zenni. A percent dropped per 100k perhaps?
Otherwise i love what you guys have done with the site The layout looks fantastic!