Hi,
It's a process that can take either 10-15 minutes or 6+ months, depending on your mobile app team.
The certs are Apple's certs, either dev or app store, installed by following the wizard as you've done above.
Marketing instance sends the messages via mta/mtachild and supporting ios jsp's, tracking instance is used for tracking user behavior.
The Campaign SDK's comprise tracking functionality alongside token registration, which enables direct opt-in from app to the marketing server (I have yet to see this used in practice).
Opt-outs are managed by an ootb workflow, subscribing to Apple's published opt-outs for ios.
Thanks,
-Jon