1. See sticky post
http://www.obitalk.com/forum/index.php?topic=61.msg109#msg109 for full story. Short version follows:
OBis can be configured via the portal or the local onboard web GUI. The former is the default and any changes made locally will be overwritten sooner or later eg when the device reboots. If you really want to configure locally, after setting up GV on the portal, you can disable remote provisioning. Log in locally, click on System Management, then on Auto Provisioning and under Obitalk provisioning, change Method to Disabled. Any settings you then make locally, including the password, will then stick.
However virtually everything you can configure locally can be done via Expert Mode on the portal. This is particularly useful for remote devices that you don't have easy physical access to. Even when Obitalk provisioning is enabled you can still view configuration settings locally. And logging in locally is the only way to see the Call History.
If using Obitalk provisioning you set the Admin password (for local access) on the portal (basic or expert mode).
2. You do not need to use the OBi as a router. As you have discovered, it is not a particularly good router by current standards. Throughput is limited to around 30 Mbit/s.
As I said in a reply to one of your previous posts, access to the local GUI from the 202's WAN interface is disabled by default. But it can be enabled. System Management, Device Admin. Under Web Server, tick the Access from WAN box. You can then connect the 202's WAN port and all your other wired devices to LAN ports on a better router and the PC(s) will be able to access the 202.
Or put the 202 into bridge mode. It becomes a 3 port ethernet switch - LAN and WAN sockets become equal and the 202's internals are on the third port. Router Configuration, LAN Settings. Change Operation Mode to Bridge and connect either ethernet socket to a better router.