1 million dollars interest in 5 days? What planet are you living on?

The interest seems to be rather ridiculously high. Tinker with the numbers and it might work.

If you want interest, then there has to be a balance. Maybe decreased payouts for crimes, drugs, ect. The game can't just add free money for the sake of adding free money.

The problem is that MR bank doesn't function like a real bank, it functions more as a vault. When you store money in a bank, you're letting the bank loan it out to people and when they pay the loans back, you earn interest. When you put money in a vault, you're just keeping it safe from PPs or muggers.

So if we wanted to institute some kind of interest system, the counter-balance to that would be implemented some kind of functional loan system as well. But then you're getting into things that players can already do without coding in a new feature anyways; so it's tricky to find a reason to make it coded into the game.

The reason there's interest is because there's risk; if there's no risk, there's no interest. And that's what you have right now. If you want interest, you have to have risk.

Maybe bringing back some kind of stock exchange for the business district could function as a way of investing?

Like people have already mentioned, if you want to add something, you have to remove something else. Just making things easier is not in the spirit of things. 

I like this idea, but it should be re-worked. Earning that type of cash is way too much. We need a checks and balance system. Always, because if we don't there would be way more money in game just floating around that is not needed. The credit market would become useless, we would not have to work hard to achieve maximum results. Dedication would be a mute point etc...

So. You should take in to account the amount of people actually playing, the amount of money per user, credits -how much they're worth. A rough guess on the average time a users are playing.

I would say  .1% interest per $5.00 or $6.00 :)

You are trying to earn interest and not make the world so easy :) Good things come to those who work hard.
 

In terms of the banking system, this is my very crude rough outline of an idea.

You borrow X from the bank. You agree to a set ammount of days to repay it. If the agreed upon date hits and you havent repaid. CAs start throwing you in jail more and more frequently.

If you continue to ignore the loan, you get throw in the jail until the entire loan is repaid.

Your idea (in it's crude version) sound very prone to abuse.

Collection wouldn't be any different than the mayor tax honestly. Just an idea, easily dismissed and moved on from.

I think it would be awesome to have a Swiss acount.