Turns out that it is possible to back up and import your subscriptions. There’s a good document describing this at Radio Userland’s support site here. Any Radio users who are reading this, not a bad idea to create a backup of mySubscriptions.opml (in www/gems) so that you don’t have to manually recreate the subscriptions file.
Thanks again to the Userland folks for their support!
Now back to our regularly scheduled programming.