Hi
Nothing at all looks unusual with this router/ata. All of the sip registration is completely standard. If the line isn't registering and asterisk is telling you that there is a username/authname mismatch, then it's 100% certain that there really is a username/authname mismatch. You need to check your coding. The device behaves like two completely separate extensions so you will need to create two extensions in SAIL.
As to the 5 character name length in the operator panel, there is only room for 5 characters at the extension density we have chosen for SAIL (we wanted to show100 extensions but it only handles 90-some). It has nothing to do with your problem. If you want to change this then you will have to read up on FOP to understand how it works and then change the values in the operator.conf files (which in turn are created by templates in SAIL, so you will have to read up on SME templating also).
You can find the templates in /etc/e-smith/templates/usr/local/operator/.
Kind Regards
S