Answer 1: no, it is referenced in the Overview iView by application configuration linking to a component configuration which has the used role and instance.
Answer 2: MSS uses launchpad but there isn't a launchpad role like with ESS. The main reason being that it works differently, you select the employee and then perform actions. With MSS, especially in EHP6 and later you should upload the PFCG role from the backend system.
Answer 3: it isn't, the link between launchpads and PFCG roles is at the application level.
See Tips & Recommendations for customizing ESS Menu (WD ABAP) and also SAP KBA 1943809 to get started...