To add a bank account go to Profile and then tap the gear icon. Scroll down to Bank Account > Add Bank Account.
Or, click on the Add Bank Details to get Paid button on your Profile page after you have listed an item.
Fill out the questionnaire from Stripe and submit the form. Stripe is certified to PCI Service Provider Level 1. This is the most stringent level of certification available. You don’t have to worry about the safety of your personal information. You can read more about Stripe security here.