Not directly, but there are several ways to do it via simple IIS configuration changes. You can just change the home page for your site to something else than default MonoX page. Of course, that would not prevent people from going to your MonoX pages directly (if they know the address), so you could open two sites in IIS, and bind the real domain to the temporary site, while working on some subdomain/virtual folder name for MonoX.
As for the newsletter supscription module, depending on your version, you might have a NewsletterSubscription.ascx in the MonoX/Samples/WebPartSample/Newsletter folder. If you don't have it, we will port the source here.