When you are upgrading to a newer version of patch manager you can just stop and restart the emintwaredatagrid service or restart the server.
Im not sure what you mean by special settings. It sits on top of WSUS so whatever settings you have for updates thats how they will go out.
You can create target groups and approve the updates to any or all of them. If you mean will it download the updates and give the user a shield icon to manually start the update process then that depends on what policy you have set for the target group and GPO