DV360 (formerly DoubleClick) definitely does.

Analytics uses first-party cookies for its core functionality. There are optional features where it connects to a third-party cookie from another Google service, e.g. connecting to the DV360 cookie to pull in demographic information.

They do, but seeing as how most users are force-feeding user data directly into Google's mouth via usage of their search engine and gmail inbox, removing 3rd party cookies from the equation is unlikely to affect their bottom-line in a measureable way.

Not if the user is logged in to the Chrome or Android