Your display name, photo and bio can be changed any time. Changes to photos and bio go back through review; your public page keeps the approved version meanwhile.
Display name, photo, banner and bio
Change them from your profile settings at any time.
Editing something already approved does not take it down. The public keeps seeing the approved version while the new one is reviewed, and if the change is refused your existing one simply stays. You always see your own latest upload.
Your username
Your username is your public address, so changing it changes every link you have shared. Contact support if you need it changed.
Your legal name
The name on your Stripe account is checked against your identity document and is separate from your display name here. Changing one does not change the other, and it should not — a stage name is not what a bank verifies against.