I'm British and to me "quite" here means "mostly" i.e. not entirely. Could well be a misunderstanding but it should be made clearer as this data is priceless.
Personally, I'd never trust the only copy of something important to a service provider--especially one that isn't a "big name." (Though even in the case of big names there can be issues with account access, etc.)
ADDED: Curious why people find this a controversial statement. I understand if you have AWS set up with various redundancies but even a service like Backblaze I consider a belt and suspenders-type backup. This is in no way a commentary on the OP but simply an acknowledgement that stuff happens.
Makes sense. You can feel vulnerable in a big hurry if your primary fails or if it turns out that one of your backups wasn't being properly backed up to.
I know a lot of people these days are fine with their stuff mostly just being stored in "the cloud" someplace. But for things like photos, I really want a couple copies under my control to the degree possible.
Another Brit. It's all in the context. "Quite" can easily be a strong superlative but it relies on shared understanding between the parties so I wouldn't depend on that interpretation.
It's fine in a spoken context as tone can add sufficient extra meaning. If you can guarantee the listener is expecting an informal register then it probably also comes across as a superlative. "I met him and he's quite unpleasant" would usually imply he was a total c*nt.
Not really, but it depends on context. The nuance is often difficult to detect when written. When spoken, a phrase like "quite extraordinary" or "quite brilliant" would usually be a superlative, as you suggest, but it would usually be indicated by emphasis on the "quite". And the adjective itself already has to be quite strong, so "quite good" will never really mean "great".
I think most Brits (I am a Brit) would write "very" when they mean "extremely" rather than "quite". In spoken English there is a lot of nuance, but if you said a meal was "quite good" it would often have a connotation of "better than just okay" rather than "excellent". Saying a meal was "really good" would be closer to "excellent".
