How do you start over on Cloud? For example, let’s assume that someone forgets to download the EC2 Key Pair .pem file during initial setup. Asking for a friend…
The EC2 key pair is never needed or used. Its presence in the CloudFormation template is an AWS marketplace requirement targeted (IMO) at data-center-ish software where you have to e.g. login to each box to change the admin password or fiddle with a configuration knob.