Blogger is a free Blogging service provided by Google hence its have own limitations. One of the bigger limitation is that it is controlled by Google so you are not Violates any content policy of Blogger. If you are violating any content policy of Blogger, Google has rights to delete your Blog without your permission. If you are want to stay clear then first read the content policy of Google. So you are advised to take backup of your blogger Blog and its contents time to time.
Taking Backup of Blogger Blog:
You can take .xml format which you can store in your computer or any cloud storage for further any risk. It is little difficult to take backup time to time. You can take backup weekly or monthly.
You can go to your Blog’ s Settings>> Others then you will see the page like above. Click on Back up content. and then you will see a popup page in which you Click on Save on your computer. Then it will save your profile locally in your computer.
A Better advise that save your file to google drive or Dropbox or any cloud storage which suitable you. The Benefit of saving your file in cloud storage is that you can access those file from anywhere on any computer.