EV Domino archiving queries

Hi All,

Please guide me on below 

1. Can I remove VSA from local admin on EV server, SQL server and EVDG after EV configuration, will EV functionalities get impacted
2. EV server and EV Domino Gateway are on different system. Do I need to configure EV on EVDG server
3. For EV Domino Journaling configuration, is it mandatory to have Domino Journaling configured on Domino server or is there any other options available

Thanks in advance