Scripts in vApp run with priviledges of user under which vApp was started.
So if you run aplication under normal user in system, I don't think you are able to start or change any service. If you run vApp under Admin, you can do whatever you want. It's same like with normal application.
Look here for more details about scripts.
Ondrej Zilinec - Cievo
...Good question is half of the answer...
***Good question is half of the answer...***