If you want to migrate a wordpress site, you can use Duplicator – WordPress Migration Plugin.
Migration includes backing up. Migration also include moving a whole site to another url. I tried 2 or 3 other plugins, Duplicator – WordPress Migration Plugin suited me the best. But I was looking for migration plug-in not backup plugin in case you are curious.
Here are inline responses to your queries -
Yes and even older, you can define how long you want to keep your snapshots in the snapshot retention policy.
Yes. The only constraint here is that you can snapshot your disks at most once every 10 minutes, if you require more frequency than that then you can go with cloning your disk, which features a rate of 1 ...