I'm trying to create a new rule using a cloud endpoint. (2.2.5) When selected the toggle in the trigger drop down I get this error: " java.lang.RuntimeException: OAuth is not enabled for this App on line 1380 (selectTriggers)"
Tagging @bravenel. I can replicate this issue--just try to add a cloud endpoint trigger to a new rule, and it happens. Since you're creating a new rule and you're on 2.2.5, this should be Rule 4.1, which is new, and I'm guessing maybe they forgot to set something to enable OAuth for this new version of the child app. But we'll see.
It's a relatively new feature, and I haven't followed it closely, but I don't remember folks having significant problems export/import on their own hub. But yes, waiting is the smart money right now.
I just tried exporting a rule from one of my hubs (download to my pc) and then importing it to a different hub (from my pc).
It worked well in that it imported the rule structure but you do have to put in the devices (the same options as you get on cloning a rule within a hub) as the device doesn't exist on the second hub, these are empty.
It does work though.
As for deleting rule machine. I would assume that if you deleted rule machine parent app then all child apps (rules) underneath it will also be deleted.
As for oauth, I don't remember it asking for oauth when the app is installed.
That's for user apps. The built-in apps should be magically configured by staff as part of what's baked into the hub firmware, so we don't need to (and can't) do this for those.