1. We have guides regarding how to set up a staging site and the difference between the active and staging site.
2. You’ll need a web hosting solution to host your BoldGrid site, but we do offer a list of recommendations. Also, notice that those Full Support
3. BoldGrid themes are responsive. They change appearance attributes to accommodate different screen sizes. You can simulate this by going to a webpage on your desktop browser, right-clicking the page, selecting Inspect Element and the Responsive Design Mode icon (in FireFox) or Toggle Device Toolbar (in Chrome).
Please let us know if you have any more questions regarding this.