When should a Storage Account be configured to use Customer Managed Key instead of Platform Managed Key?

Can we use Customer Managed Keys for a Data Disk attached to the VM and possible to rotate the keys every 6 months? If this is possible, can we automate the process using azure automation agent?

If an application team accidentally deletes a Customer-Managed Key from Azure Key Vault, what impact would this have on data availability compared to using PMK?

What happens to encrypted data if a Customer-Managed Key is disabled or deleted from Azure Key Vault?

Is it recommended to start with a Burstable VM for development or testing environments and later resize to CPU or Memory-optimized VMs for production?