1. Adding admin does not solve the your problem.
2. After connecting the cable from the ISP, options that you need to be locked - hide.
3. User admin has additional access:
a) Power Management
b) USB Service + Media Server + Print Server
c) Wireless -WDS
d) VoIP Call History
e) VoIP Call Rule
4. Only flesh to the factory fw leaves all options open.
5. With factory fw everything works ok. if you know your SIP data and username and password for DSL connection.
6. All these data can be drawn from the router but no one wants to publish it, because ISPs could change security settings, and then everything would perhaps locked.