API Questions - Suggestion

When I become rich I'm thinking of opening a Bank and offering Credit Ratings for Loans.

My question is, I know I'd have to have a Banking Database, but are you allowed to make an API in which people 'Deposit' or 'Withdraw from Bank.
When Deposited it goes to Private Island Vault and Database with receipt.
With Withdraw it transfers from Torn to Database and leaves PI with receipt to customer...
Is this allowed?
What languages do you suggest?

Are you asking if you can have the API can make actions for you?

Yes

The API doesn't allow for full automation, and iirc full automation (i.e. zero user input) is usually forbidden here.

EDIT: Read HERE for general API rules

This is not allowed.

The API is ready only.

The closest thing you can do is:

Hire a person to be your "cashier". Get your "cashiers" API-key to watch their events. Your cashier can still run away with your money, but at least you'd know when they do so.

As above, it's not allowed.

But just to satisfy my curiosity, what's the purpose of this idea, what motivates you to rent out banking space? There's faction bank, cayman, and others option available. If it's your private vault, there's an upper limit of 1b, which is not a lot of money if there are 20 people depositing with you. (10 days of travelling can easily get 45-50m).

Are you giving an interest-free deposit or is the money for you to do investment like a real bank?