Let me describe.

As per envato License system, you can use only in one domain per purchase. If you need to use it in multiple domain, you need to purchase it multiple time. You can use 1 Domain = 1 Purchase, 5 Domain = 5 Purchase.

1. You’ve to edit code for customization anything, please see the root/resources/views for the view page, root/app/Http/Controllers to get controller files and root/app for the model files
2. for the change banner, you need to change this image root/assets/images/main-banner.jpg
3. Yes, the translation is very easy, just follow the steps from language menu, but you are looking for multilangual, which you need to develop.

Multilingual means you can integrate 2 or more language, and translation means you will change the site language.

Best regards