In answer to your questions:
1. To get an idea of how often releases have been made, you can review the version history
here, and for more details regarding upcoming releases, you can read the
theme release status page.
2. The responsive version of ClassiPress will be available in the next major release (v3.3), the release date for which is indicated on the theme release status page linked above.
3. Removing default layout features and price tag would require some modification of the default theme files on your part, and although you can create custom forms for ads, removing most of the fields, the description field will still be there by default and again would require some modification in order to remove it altogether. ClassiPress is not encrypted, so there is nothing which would prevent you from making these changes if you wanted to.
4. There is no "favourite" or "report ad" functionality built into the theme. Ad posting requires registration, so this would require modification if you wanted to allow ad posting without registration.
5. You can find
recommended plugins for this here.
6. Not at this time, but you can find a
grid view child theme and map related plugin for ClassiPress in the
AppThemes marketplace as optional add-ons.
7. Through modification, yes this can be done, but there are no specific settings for this in the ClassiPress admin dashboard.
8. This would also require customization. Thanks.