A. Yes, you can switch between 3 different providers: Eyeota, Bombora and Experian (US).
You can switch between these providers in the Third-party Index tab, both in the Audience and Campaign sections, under Insights. To do so, use the 'Provider' filter:
If you have any further questions or have a specific request for a different third-party data provider, please get in touch with the customer support team and we'd be happy to help.
You can contact us either via email at firstname.lastname@example.org or via the LiveChat icon at the bottom right of your screen.