Just like the WIX editor, you can change and customise anything on your site. You will probably find some changes you would like to make and ADI is perfect as it allows you too. The only difference is, if you want to change a part of the site, all the information shows in a column to the left of the screen. This can make your use of the ADI much quicker and get your website published as quick as a possible.
Hi Glyn, You can indeed keep your domain name. Domain registration is a separate process to site building, so there's no risk of getting one stuck on a platform you don't want to use any more. Wix is great at walking you through the domain transfer process step by step when you sign up. There's an official video guide here if you'd like a sense of how it's done. Hope that's helpful! Ta, Fred