1. That is possible with the Multiratings addon: https://wpgeodirectory.com/downloads/multiratings-and-reviews/
2. Yes, use the payments manager and set paid listings to featured: https://wpgeodirectory.com/downloads/payments-manager/
3. Users can delete listings but not reviews.
4. You can do that by setting the country to only use your default country:
GD > Multilocations > location settings tab > Country > Enable default country (country drop-down will not appear on add listing and location switcher).
5. All listings in a Custom Post Type need an address and map normally.
But you can have Custom Post Types that do not use addresses for any listing.
Go to GD > general > general tab > Select CPT to disable physical location
6. Those settings are at WP > Discussion
7. That is not possible.
8. That is how the search already works.