Can the instance be downloaded to the local computer

You can create a local copy of your Linode's disk via ssh - the instructions for how to download and upload a local disk image can be found here:

https://www.linode.com/docs/guides/copying-a-disk-image-over-ssh/

For alternative backup methods we have a pretty comprehensive guide that details various methods and their use-cases:

https://www.linode.com/docs/guides/backing-up-your-data/