Somehow, I've finally got it solved, although I'm not sure I could do it again. The portal is horrible.
Here are some of the problems I noted along the way:
1) Restoring your backup file in Obi Expert does not add your other service providers to the dashboard, even after you add in your passwords and get them working. They read unconfigured forever on the portal.
2) It also won't let you restore your speed dials.
3) If you restore your speed dials "externally" (that is, directly to the device using its "Update" or manually), it will nuke them again.
4) If you take your device offline and then put it back, the portal might make your GV stop working.
5) If your GV stops working while attached to the portal, no amount of trying to replace your credentials will work. At best, even if you delete your SP1 and start over, you will end up with a second GV installation on SP2, which if you were planning to use for another carrier leaves you out of luck.
6) Only way I could get a clean GV installation on SP1 was after a factory reset and after deleting the device from the portal and adding it back.
To my mind, this is madness. A properly designed portal should allow you to:
a) add a device without it making any changes to it,
b) select what changes you want to make or services you want to add,
c) let you apply a backup file to refresh or install your other service providers, and settings (including speed dials), and display their existence on the dashboard,
and
d) leave your speed dials the hell alone unless you want to change them.
Speaking as a user and as a (now retired long-time) systems designer, to my mind this is very poorly designed, user-hostile, and counter-productive. Which is why I hate it to pieces. How hard would it be to fix it to comply with the above? It would make it infinitely more lovable.
By the way, using XML Notepad, I actually had to edit a speed-dial-only backup out of the earlier backup that I could restore after I got everything else working and blocked Auto Provisioning.