In answer to your questions (I'll just use regular numbers if that's ok? ;) ):
1) Vantage does not have multiple user types built into the theme by default, so this would require customization on your part.
2) By default, users select their own password when they register, so this would also require customization to change the way new signups are managed.
3) There are no options for this, so it would require customization.
4) Yes there are advertising widgets available in the admin dashboard which you can configure and use Google Adsense if you wish.
5) You can share the user database via a
WordPress multisite setup, however you'd likely need to refer to the WordPress Codex to find solutions for sharing data.
6) This is not a feature of the theme, so would require customization.
7) Not specifically, you can see the available options for plans
here.
8) Yes to both.
9) We have received a French translation for v1.3 which is in the process of being reviewed and will be posted to the languages page. You need to use the translation for the correct version.
10) You can find a plugin suggestion on the
recommended plugins page.
11) Vantage is not encrypted, so yes you can customize the theme to suit.
12) Potentially through use of a plugin or customization, however this is not available by default. Thanks.