The command you list are correct for changing ownership of files that you’ve already created. In the future, however, you should use the “user1” account whenever you are working on the site to ensure you don’t have any future problems. There are two reasons for this:

1. Depending on your configuration Vesta may use suexec to run scripts. for security purposes, suexec will not allow a script to run if it is owned by a user that is not the one running the process. Since all scripts run under the user that the site is assigned to, files owned by root in the public_html directory will not work if your server is configured this way.
2. As a general rule, you should only use root when you need it. Root is all powerful, so it can be really easy to accidently do things you don’t mean to do, like deleting important files because you aren’t in the directory you thought you were. Working as “user1” is safer because you won’t be able to don anything that effects the entire server or the files owned by any other user.