Yes. Your credential will not be deleted. You - and others who want to view your certificate - will still be able to see your credential. The main change will be that a warning box will appear above the credential stating that the credential has expired. This is so that it is immediately clear to employers, or evaluators what the status of the credential is.
Yes, you can still make modifications like 'Add Evidence', 'Request a Name Change', or 'Change Privacy'. If you do make changes to your credential, remember that your credential will still appear with the expired notification.
You will no longer be able to add an expired credential to your email signature - as this will not communicate to viewers that is has expired. You will still be able to download a PDF copy of your certificate, but it will have a stamp communicating the date on which it expired.
The best way to renew your credential is to contact your credential issuer directly. You may need to provide supplementary materials to them directly, and Accredible will not be able to help with that process.
When you retake a course you will be issued with a brand new credential, which may be sent through to you sometime after your old credential expires depending on the processing time for your issuer. Your old credential will remain expired.