1. in the starting screen of PFCG press go to->settings and select the complete view - then you will see the workflow tab in the rule maintenance screen.
3. doing the assignment from PFCG to the tasks or PFTC to the roles is the same assignment and can be done in both transaction - do what is easier for the specific requirement. one role linked to many tasks via PFCG, one task linked to many roles via PFTC.