Hydra is open source software, provided as-is with no warranty. As with any blockchain, no transaction can be reversed or canceled. You are entirely responsible for your own security and it is NOT recommended to use your daily computer for staking as there is a high chance that your computer might be compromised without you knowing it.
The guides provided as part of this info-site do not guarantee you that you will have a 100% safe staking environment for HYDRA. In order to minimize risk, make sure you always work with a clean install on a new device that never had any history of internet browsing as well as running third party applications and/or to have been involved in general everyday usage.
Always make a backup of your wallet and make sure you keep it in a safe place (offline device and/or paper wallet).