Can a custom cloud image be deployed to a VM?

Yes! Administrators can upload custom cloud images on the Dashboard page, Compute >> Catalog menu, so users can select them to deploy to a VM.

Is there a fee charged to the user when the VM is stopped?

When the VM is stopped, the user will be charged for storage. For that we apply separate prices for processor, memory and storage. Admin can input prices for each component in the Compute - Pricing feature.