Yes. The demo content is same as our live site excluding the images. We are using paid images on our live site so we can not distribute them with our demo content. So we are using free images replacing all paid images. Also the text content (heading, title, description etc) are same as our live site. So all the content is same.
Yes, all updates for ThemetechMount all themes are life time free of charge.
You don’t need to add activation code for revolution slider & WP Bakery plugins. We purchased extended licence for both plugins so we can distribute it with our theme. The plugin is same as you are purchasing separately (as called Regular Licence). The only difference is auto-update and some ready templates. But both features are not required with our theme as we are releasing plugin update via our theme update and we are providing templates with demo content setup too.
So you can ignore it and use it legally. They are providing the feature so you can use it if you already purchased it separately.