If you lost your Droplet’s SSH key or root password, reset the Droplet’s root password in the control panel. You can use the Recovery Console to regain access to the Droplet’s SSH configuration.
Snapshots do not retain the IP address of the Droplet they were created from, but you can use floating IPs to assign the same address to new or redeployed Droplets.
High RAM or CPU usage is normally the result of applications or kernel processes on the Droplet. You can monitor high CPU usage processes on the Droplet and stop them if necessary.