I researched related topics but I did not quite understand some things, could you clarify some doubts?
1) How can I back up a specific site on the multisite network or would it not be possible?
2) I'm used to making wp edits directly in the template folder, however I went through a test and found that instead of a change working on a site only it replicated to all sites on the multisite network.
3) Do you recommend some plugin to manage the domains? I tried to use WordPress MU Domain Mapping, but it did not work on a video I saw enabled a field to manage the most domains did not appear on my.