1) Yes we will offer a translator discount for a verified theme which you can use towards your first theme purchase (as outlined on our
languages page). It does not apply to plugins, and can only be used during the purchase, not refunded after purchase. You can send the file to support at AppThemes dot com.
2) Items in the marketplace require the parent theme to be installed before you can use them, child themes will not function without the parent, so yes you would need to have ClassiPress first.
3) Without knowing what version your friend is using, or what their situation is, we can't comment as to why he's getting it, but you can of course use plugins or moderate posts before approval if you have concerns about spam. It's not a common complaint/known issue specifically for the theme. Thanks.